guran if you bought boxing clever concertina compilation you would hear what duet playing of blues can soiund like and how it is related to boogie woogie piano walking bass.
"concertina reeds do not offer the same means regarding forced control of the wind as the harmonica reeds do." Try slowing or speeding your bellows movement--crude but effective.
concertina steel reeds are much thicker than harmonica reeds, and need excessive force, then if you do eventually manasge to bend the note you have to spend money getting it retuned, completely stupid idea
   please do not lecture me about controlling bellows movement, I know all about bellows manipulation i have been playing for 43 years