The key ↔ harp calculator
Enter the song's key: the hub tells you which harmonica(s) to use and in which position. The other way around, pick your harp (a C, an A, a G…) and it lists every key you can play with it. No more guesswork before you step on stage.
Understanding the positions (1st, 2nd, 3rd…)
1st position (straight harp) plays in the major key of the harp; 2nd position (cross harp) plays major/blues a fifth above — it's the go-to position for blues and pop; 3rd position opens up the Dorian mode. Each position is explained along with what it brings musically.
The interactive Richter layout
The standard diatonic harmonica uses Richter tuning. The hub shows the layout of all 10 holes (blow/draw) and highlights the tonic holes for the chosen position, so you can spot at a glance where the anchor notes fall.
- Calculator both ways: key → harp and harp → keys
- Every position explained, with its musical color
- Richter layout of all 10 holes, tonic holes highlighted
- Manage your set of harps (C, A, G, D…)
- Built for blues, pop, folk and song
Method, data and sources
The count above reflects the Music Hub's real catalog — 2,597 songs as of July 26, 2026 — recalculated on every site update, never a frozen estimate. A song counts as "playable" if at least one combination of an owned harp and a position (1st, 2nd or 3rd — the ones actually used on stage; positions 4/5/12 are excluded) plays in the song's key. This calculation is public: the documented API at /api/v1/harpograph/collection returns, for any set of harmonicas, the number of playable songs and the next titles unlocked per harp — for example ?harps=C,A,G.