Thanks for your post.
The question of how chords are entered is in a way fundamental to both the role we see Hookpad playing as a songwriting sketchpad and the spirit of Hooktheory in general. This topic has been discussed in other posts before, one of which I’ve quoted below.
In summary, there are many programs out there that allow you to compose music using arbitrary chords. Hookpad is different in that chord progressions are written from a functional perspective that encourages users to think about the music theory behind their songs, as well as songs analyzed in the Theorytab database. We believe that doing so provides a richer experience in the long run by teaching useful songwriting techniques.
Nearly all popular music fits nicely within this framework, however there’s always going to be some music, perhaps jazz, or movie scores that doesn’t, either because it doesn’t use functional harmony, or it drifts between tonal centers, or both. This is a tradeoff that we’ve chosen for Hookpad.
That’s not to say that we won’t support an “arbitrary chord” option in the future, but it’s not in the current plan.