I saw Toots Theilmans play on TV once, and he had a whole bunch of chromatic harps that he swapped among. Which got me wondering.
Do chromatic harmonica players use one harp for all keys, playing in different ‘positions’? Or do they use different ones for different keys, like diatonic players generally do? Or some combination of the two?
Although I’ve known a few really good diatonic harp players who could play as many as five positions on a single harp, most diatonic harp players use different harps for different keys. Even mediocre ones like me can play in two positions per harp (e.g., a C harp is used to play in C major and G blues).
As I understand it, Toots was at one time recognized as the only harmonica player capable of true jazz improvization on the chromatic harp. So if he uses different ones for different keys, I assume everyone does.
(For non-harmonica enthusiasts: a chromatic harmonica contains all twelve notes in the scale. It has a little button that changes the available notes. The more familiar diatonic harmonica contains essentially only the major notes in the scale. Sort of like a piano with only white keys).