G'day folkfan73,

Harmonicas were quite commonly the first instrument for ordinary folk to play from childhood... from mid/late 19th century on. "Blues" is just a sideline, involving playing "cross-harp" (lots of draw notes dominaing) to get a Mixolydian mode (essentially the same as a "blues scale". Almost any old folk song in Western traditions plays happily on a simple 10-hole harmonica.

Modern / 20th / jazz / &c may require extra accidentals / semitones and might need a chromatic mouthorgan (think of Larry Adler, &c) but you can spend the rest of your life happily playing good folk music on a simple 10-hole harmonica.

Regards,

Bob Bolton