Music is a business. You have to decide how seriously you want to pursue your personal enjoyment versus making money. This is not to say that you can't have both and sometimes if you plan carefully you can have a rewarding experience in every way.
Many of you have played music on different levels and it's good to talk to other musicians to get ideas and learn from their experience. Some musicians are happy to rehearse together only, some are happy to do cover songs and others write and play original content and go for the big time. No matter what you decide, the planning of your endeavor is a most often ignored and important part of your success.
DEALING WITH CHANGE AND KEYS TO SUCCESS
I think it might be a tie between the number of bands I've been with and the number of cars I've owned, especially when I was younger. Playing music can be very frustrating. There may be times in your life when you will participate more and sometimes less. Keep at it! Music keeps you young and alive.
Change is all about being adaptable. Music styles, Band Members, Gigs, and most of all - you change. Keep you eye on the prize - playing as often and for as long as you can.
Don't get locked into the same old music. Some songs are treasures and you will want to play them forever. Put some new stuff in there every once in a while to challenge yourself and keep things fresh. There is nothing more frustrating to hear a good band, and years later they are doing 80% of the same old stuff. If you have old hit songs that may be the exception. Don't be afraid to do original music. Economic times are tough. People want to enjoy themselves when spending their money listening to music. Give them your all.
Circumstances cause changes in band membership. The band will usually be different when a member is replaced. In one band we lost our keyboard player and went on without one. We wound up with a tighter sound, more gigs, and more money. Pick average musicians you can get along with rather than superstars who want to run the entire show. After auditioning replacements, talk about what you have to change. You new guitar player might not be the soloist your old one was but maybe he can sing better and open up more avenues of songs for you to do. If you get a chance, read "Who Moved My Cheese" by Spencer Johnson, MD.
Music is all about entertainment. I am not suggesting you get a monkey and organ grinder. Act like you have an interest in what's going on. Have confidence. You're probably much better than you think. If your band makes mistakes on stage (I call them clams), don't turn around and look at the guy on stage like he just wet his pants. If your whole band screws up a song, keep going or restart and make a joke of it to the audience.
"Dead Air" is your biggest enemy. Don't let time go by without communicating to the audience. I played in "show" bands where your every move and words were rehearsed. I think I would have rather worked at the steel plant. A natural, honest, and upbeat presentation will keep your audiences attention until the next tune.
Communicate with each other on stage. Hand signals or a few words can serve as a reminder for stops, endings, dynamics, and a variety of things. Speaking of dynamics (getting louder or softer is a general definition of dynamics), they can make or break you. Music with a constant loud or soft approach has little feeling. Build your songs and make great dynamic endings. If you are doing covers, don't be afraid to change things. Make each song your own.
Right now I have been in a great band for over two years. We enjoy rehearsal, gigs, and have tons of fun with oldies, blues, and a little country. I hope whatever your musical experience is, that you make it fun too.