1. the accordion was the premiere jazz instrument until the 50' when the shift went the guitar and then the electronic keyboard. you can bend notes with an accordion, just like a harmonica. 2. sounds - which model to buy. just like a car, depends on what you want it for. each instrument has a different voice. the reeds vary in quality (student grade and up). then its the bellows that are use to give the expression and vocal quality to those reeds. 3. sexy - tango - mostly done on bandoneon ( another member of the family) suggest Astor Piazzola or another- "The tango project" think scent of a woman. they are the trio (violin, accordion, piano) playing in the background. you want earth - then the king "Cliton Chenier" zydeco (he plalys the piano, not the button box) - 4. finnish - tend to play chromatic button - they are known for their tangos - REALLY- 5. the bass configuration is really quite simple. circle of 5ths, and the counter basses are a 1/2 note down. makes it easy to change key. - this does not work for the freebasses which are individual keys - ergo you can play piano music, l and r hands, as written.