Diatonic harmonicas are mostly used in folk, blues, country, and rock. They come tuned in a specific key and are easy to play in 2-3 different keys but it gets very technical if you want to play in all 12 keys with a single diatonic harmonica. You can get extra notes on a diatonic by bending and overbending.Read More - https://harmonicaland.com/en/module/tvcmsblog/single?id=18&rewrite=what-harmonica-keys-do-you-need&page_type=0