Do you love jazz? A lot of people do. Well you might've been thinking of starting a jazz band. If you're not sure how to do that, hopefully after reading this you'll know how.
Listen to jazz. Before you even get your band together, make sure you know what jazz sounds like so it's a lot easier for you to write original songs.
Learn the church modes: Lygian, phrygian, locrean, and blues are the most common. Learn the wholestep/half step patterns and you can play all scales (you can also just learn the realationship between the modes. Ex: the phrygian scale is the major scale with a lowered 2, 3,6,and7th scale degree). The pentatonic scale is also a good one to learn for solos.
Decide if you're going to be an instrumental group or a vocal group. Obviously the difference between those two is that instrumental groups don't have singers, and are more like small jazz orchestras. If you have a vocalist, they need to have a good range of singing styles.
Get a pianist. They should be able to play well and should have a fluent knowledge of jazz chord progressions.
Get a drummer. The drummer should be able to keep a steady beat, and should be able to play quite fast.
Get one or two guitarists. They should know how to read real notes(not tab) and at least one of them should be able to solo.
Get a bassist. They will be able to provide a good solid foundation over which to play. they should be able to play both double bass and electric bass.
Get a trumpet player. They should have fairly good tone and should know basic tricks like trills and vibrato.
Get saxophones. Saxophones are the spirit of jazz, and they are extremely important. You will need a tenor sax, and an alto sax. If you like you can also get a baritone sax. (if you dont get a baritone sax, you probly need to get a bass trombone)
Decide on whether or not to have a singer. If you want one, you'll have to decide on whether you want a male singer, female singer, or both! They should have good breath control.
Come up with a genre. Well obviously jazz, but what kind? If you don't know exactly you can find a list of genres here...
Make a band name. It should reflect your style, but it can be anything you like! Just get your band together and brainstorm band names.
Start practicing! Practice a lot! The more you practice, the better! There's no such thing as perfect. When you're practising, just make sure every one's following along, and not behind. If anyone is having trouble, try to help them. If they refuse to practice, replace them.
Start writing songs. No band will get anywhere if you don't have an original song list. Write some songs, and lyrics, and make sure the whole band is involved. You should only start writing original songs when you think you're ready, and when everyone is confident in playing many covers, and you should all be quite experienced musicians by this point.
Start searching for gigs. You can start off with parties and basements, but once you become a little more well-known, you shouuld ask around and play at your local jazz bars, clubs or whatever! And don't forget to keep practicing!
Have a myspace. It will drastically help you with marketing, as lots of people will be able to hear your music, and fans can check your blog for news.
Record a demo. It should have at least five songs. Put your best song on track one, and your second best on the last track. You can now send this demo to record labels, and sell them to fans at your concerts.
Just have fun! You might not get signed, but you can have fun playing local shows, and hey , you never know...