This might have been quoted on the list but to make it simple, you don't need a lot of musical theory or blows and draws compared to the band.or guitar player. It is easy in second position:
Band G Harp C Band A Harp D Band B Harp E Band C Harp F Band D Harp G Band E Harp A Band F Harp Bb Band Fis Harp B
I carry this card with me all the time and even with professional musicians it never went wrong.
Harri Finland