Music is a communal, social activity. The image of the tortured, solitary musician, locked away at his piano for days at a time, is I think one that arose quite late and is probably one of those odd Romantic ideas. The fact is that since early humans got together to chant, sing or bang drums, music has been something to do with other people. Even solo instruments such as the violin depend on other instruments to give them the harmony background, while unaccompanied piano (to my ears anyway) stops being interesting and starts sounding monotonous after about 45 minutes. Instruments like bass or drums were designed to be played with other instruments, and if you play either of these but don't want to play with others then I would have to ask why you chose that instrument in the first place!
Over the years I have had to learn the lessons of playing with others, some of them hard. The following are just a few thoughts on these. Playing with others can be done at any level, from a bunch of friends to high-earning professional level, and happiness often depends on finding the right level for yourself. See the Cyberlizard Chequered Musical History if you want to see how not to do it.
Most of us start learning our instruments when we're still at school or college, and in many ways this is a good time to learn as you can often easily find like-minded individuals who share your interests and, better still, your taste in music. There are however difficulties at this stage in life: finding a place to play, getting there, and agreeing on what you want to do when you do get together. Most parents don't mind guitars or unamplified instruments if they're not too loud, but a lot of families will balk at the idea of a drum kit in the house, not least because of the neighbours. The British seem to be at a disadvantage here as most of our houses lack the basement that is so common on the Continent and in North America. You may be able to use school property after hours as long as somebody is around to lock up, which may restrict your time somewhat, or you may be able to hire a church hall or community centre or similar. If you do use a garage, be warned that the soundproofing is often virtually nil (those walls weren't designed to keep the car warm, after all). You may have a practise studio in your area, which is often the best solution even if you have to pay to use it. Now all you have to do is get your gear around, which if you are under 17 certainly depends on someone giving you a lift unless you want to carry your instrument on public transport - not always practical or desirable. This is another side effect of learning to play music - you may need to get a driving licence as quickly as possible.
Playing with friends has the advantage that you often know one another beforehand, making it easier to get on. However, it can also make it harder to be decisive, usually when you have set up and are now all wondering what to play. Some decades ago, when music fashions were much more pronounced and one-directional, usually most people knew the music of the day and could play it without too much strain, usually jazz standards or blues or rhythm 'n' blues numbers such as Chuck Berry. There is that old fallback, the twelve-bar blues jam, but after a few minutes this can get pretty repetitive. Really it's a good idea to agree before you get together on the sort of thing you want to play. The other thing, and one that is a good way to get into songwriting, is to bring along some chords or a bassline or whatever that you have put together for the others to play or jam along to.
Sooner or later, as you get more experienced and if you still want to form a band or similar, you will probably find that you need to try to recruit people from outside your immediate circle of friends. This applies particular to drummers, of which there never seem to be enough to go round.
There are two aspects to this: the practicality of finding people, and your own capability to work with other people. The practical side involves finding a way of getting in touch with other people. In the old days (before the Internet) it was straightforward: you just put an advert out in the section of a music paper or publication that was known to be read by musicians (in London, in the 1980s, it was Melody Maker and Loot), stating your instrument, your area and your musical preferences. Nowadays you can easily place your own ad on one or more of the well-organised websites for musicians and DJs or trawl through them looking for other musicians.
Some people fall at this first hurdle, being too shy to try to fit in with others they don't know, but in my opinion this is a pity and should not be an excuse for not at least trying to get along with other people if you want to play music. As we get older we tend to get more picky and choosy about whom we spend time with, but certainly when you're young the world is your oyster and most people under the age of 30 seem to have the knack of fitting in. Of course there has to be a certain amount of mutual trust for anything involving people working together, but then sociopaths and creeps rarely last long in groups anyway. The history of rock may be littered with "characters", but history also shows that when their personality became too negative or destructive they were either jettisoned or jumped themselves. People may tolerate mild drug taking or heavy drinking, but they are less likely to put up with serious self-abuse, thieving or parasitism, and those who act in anti-social ways often ending up losing their place and gaining a toxic reputation that is hard to shake off. I know of one professional bassist who was a fair musician but who sadly let drink get the better of him, and who eventually lost his place in a group. If you do find yourself in an unsatisfactory situation, then of course you are free to walk.
Inevitably in most groups of musicians playing original material, some sort of creative tension arises. Even if all appear to be agreed at the beginning on the general path to be taken, people either find fresh directions (not necessarily at the expense of earlier ones) or feel that the material being created is not necessarily to their liking after all.
Of course, if you signed up to a folk group but secretly wanted to play soul instead, then perhaps you made the wrong choice to start with. At this point you have the choice again, either to leave the group and find something more akin to what you want to do or else stay on for the sake of experience. However if you are in the musical minority then it is unfair to expect the others to change their tastes and musical hopes to fit around yours. Most musicians are willing to compromise in some areas but are unlikely to change the fundamental genre of the outfit, especially if it is to just suit one person. For example a heavy metal band might play one or two punk-style songs, or do their own version of a punk standard, but they will probably never change to being a punk band, any more than jazzmen will suddenly decide to play reggae material as a large part of their set. This is why it is important to make sure at the outset of a musical project that everybody at least knows where they stand, even if the individuals have widely ranging musical tastes. It's the same as with dating: don't pretend to be something you're not!
The lesser problem arises where all the members are pulling in roughly the same direction, but some dissatisfaction is expressed with such areas as material, dress code, and whether the spotlight falls too much on one particular instrument. These things are usually negotiable with a bit of give and take on both sides. Sometimes it is easy to be too precious and walk out when really the problem can be solved by compromise within an acceptable degree. A musician who keeps walking out every time they feel their musical vision is not being accomplished may end up with an unenviable reputation for awkwardness and unreliability. In such situations the question to ask yourself is whether you can possibly get along with the existing outfit or whether you are prepared to face another period of playing on your own and looking for something closer to what you aspire to.
A bigger problem that may arise for some people, especially those with religious convictions (and I include myself here), is the overall ethos of the group. One point of view might be that it should not be a problem playing with others who don't share your convictions any more than it should be for the person who finds themselves working in an office with a bunch of people of various beliefs or none. This is true to a point, but on the other hand a practising religious person would no doubt feel uncomfortable in such an office if, say, ripping off the customer was the normal practice, or regular fiddling of expenses. As with all things in life, much depends on the exact situation. However if you are uncomfortable with the content of the lyrics, or that virtually all of the bonding within the group is done on the basis of drug taking, then you will most probably feel happier elsewhere. By the same token, it should be noted that playing together with only people of the same convictions as yourself does not necessarily mean a trouble-free passage!
Another area that can sometimes lead to trouble is what one might call the authority structure in a group of musicians. In some groups, particular classical/orchestral based groups, this is not a problem: there is a clearly defined leader, usually the director or conductor, and members join in the implicit understanding that they take (reasonable) orders from that person. In jazz groups this also often pertained, not least because the leader's name was often in the group's name! In pop and rock combos this can be more unclear, leading to some tension. To take historical examples, the Beatles started off as a group of roughly equals where Lennon and McCartney supplied the material but each member was seen to represent a different facet of the group's personality. Over time Harrison apparently became resentful that his own material was being suppressed, while Lennon and McCartney ended up disagreeing over management issues, leading to the breakup. In Cream Bruce and Baker, according to Eric Clapton's autobiography, both strong natural leaders with the not entirely surprising result that arguments were common. Occasionally one person emerges who effectively controls the group, in some cases writing all the material and dictating who stays and who goes. This became the position towards the end of Roger Waters' tenure with Pink Floyd, which was to lead to great acrimony in the following years.
Being a "dictator" in a group may be justifiable if that musician is a big name with a good track record in terms of artistic achievement, or is paying the other musicians to support him/her. Even then such people can leave a trail of annoyed and disillusioned sidesmen and one-tour members with tales to tell. Acting as dictator when your own track record is no better than the other members' usually rankles with other people and will often cause them to leave, leaving you without people to play with. However "democracy" has its problems too. In a group where everyone says "we're a democracy, maaaan", the problem of the lowest common denominator can prevail, ie there is no quality control, no discipline (people turning up late or not at all, not paying their share of the studio time, etc), and no direction. This can be aggravated if the ethos of the group involves a lot of drinking or drug taking as part of its musical activity, since such activities tend to enervate decision making and other necessities.
Usually the middle path, and one that seems to work best, is to understand from the beginning who is contributing what to the group, whether it be musical material or management activity such as going out and getting the gigs. In time a natural leader may emerge in the group whose leadership is tacitly accepted by everyone, or else each individual may feel secure enough in their own position in the group to be able to agree on decisions with the rest. Newcomers to a group setup should probably not feel automatically entitled to "full voting rights" until they have played in it for a while - much depends on their contribution and personality.
One final topic needs to be addressed, and that is the painful one of parting ways. Sometimes this is a mutual decision, where everybody either feels that the group has run its course for whatever reason, or simply because life outside intervenes in the form of, say, people moving or having children. Such partings need not be acrimonious, and it pays to stay in touch with fellow musicians with whom you may find yourself playing several years later. The more difficult aspect is when it is felt that it would be better to part with one member of the group, which, like it or not, is usually referred to as sacking! This tends to be either for reasons of musical competence (or otherwise) or for reasons of personality. Before taking this step, members of a group should ask themselves in what way the group would be better off without that person, and whether they can or should be replaced. Also, how serious is the group to start with? If it's just a bunch of friends or casual players, sacking may not be worth the bruised feelings it may cause. On the other hand at a more serious level, particularly if the group is a secondary or primary source of income, then dropping the member in question may be the only realistic chance for the group's survival. I have heard of scenarios where most or all of the group were threatening to walk out unless the offending person was dropped - a sad case, but not unknown. At this point it may also to pay to examine yourself and check that you yourself aren't becoming a toxic personality, even if you feel you are pursuing the artistic dream.
Playing with others doesn't always need to be a serious affair. Providing somebody can at least think of or provide some songs, whether their own or other people's, then there's no reason why a one-off jam session with a few friends or local musicians shouldn't be just as enjoyable as a regular group - and often it can be less stressful! It's also a good way of making friends and contacts, both on a personal level and a musical one, should you or they need somebody to take a place in a group or outfit in the future.
"Jam nights" are now quite popular in many parts of the UK. Basically these take place in a pub or club and are the musical equivalent of "open mic" night, ie you turn up with your instrument, get your name down on the list and then get up and play with a group of others when it's your turn. To get the most from the night it's often best to play as an individual with other individuals rather than turning up mob-handed with your own group, getting up there as a group and playing your own three songs, although that can also be valid especially if you invite others to play with you (something we often had to do in the early years of the Space Truckers when we lacked a drummer!). The potential downside of jam nights, at least in rock-orientated venues, is that it's easy to be reduced to playing 12-bar blues much of the time, which requires good play to make it sound interesting after a while. The other problem is that if you're a guitarist, you will probably be one of a large crowd of guitarists and have to wait a while to get up there, if you get a spot at all. Having said that, whatever's going on on stage (within reason), jam nights can be enjoyable from both the participation and spectator point of view. It's also a good way to test your mettle as a musician - sometimes the most basic mistakes can show up!
I've covered playing in church elsewhere in the Music section. Some of the same considerations apply, however - musicians playing hymns and songs of worship are no less human than the rest of the world.
Contrary to the youth image traditionally conveyed by pop and rock, music is not and should not be an artistic medium confined to the young. A quick look at jazz history will show that many of its finest artists were playing well into old age, restricted only by the infirmities and frailties that come to all of us in the end. More and more middle-aged men (and no doubt women) are hanging on to their guitars and forming or reforming bands of like-minded individuals, and while it's easy for the young to laugh at this as "dad rock", surely it's a healthier pastime if done responsibly (ie not trying to relive one's youth) than just sitting at home watching the television. Music is supposed to be one of the things that brings people together, like sport. It would be good if this could be used to bridge the generation gap and other social divisions on the informal level of people getting together simply to play music and enjoy themselves.