In the context of music, the letter "A" refers to a musical note, and the number "7" refers to a chord. The chord is called a dominant seventh chord, and it is built by taking the first, third, fifth, and seventh notes of the A major scale. The letter "m" stands for minor, which means that the chord is a minor chord rather than a major chord. So, the chord "A7m" is an A minor seventh chord.
Which is wrong - that's Am7! (BTW without any further qualification a "7" is assumed to be a minor 7th, even for a major key - and you can even have Am maj7, i.e. an A minor chord with a major 7th - i.e. a G# - added). A7m doesn't mean anything to me - even if it were Am7, it's not a key a piece can be "in"...
Oh and also "a dominant 7th" chord is specifically the chord formed on the fifth note of the scale, so a dominant 7th in Am is an E7 chord (and a dominant 7th is always a major chord, with a minor 7th!).
Edit: I asked it whether it thought A7m made sense in that context...
"A7m is not a meaningful description of a key that a piece of music could be in. In music, the key of a piece refers to the tonal center around which the melody and harmonies are built. Keys are typically designated by a letter name, such as C, D, or E, and may include additional information about the type of scale (major or minor) and the presence of any accidentals (sharp or flat notes that are not part of the key's natural scale). For example, a piece in the key of C major would be indicated as "C major" or simply "C," while a piece in the key of A minor would be indicated as "A minor" or "A.""
(there was a second paragraph attempting to convince me that A7m was a description of chord, similar to what you posted.
Note that the above description is basically correct, though the way it describes accidentals is not quite how I'd put it, plus it would be unusual to ever say something was just in "A" if it were actually in A minor).
(I then got it to give me an example of a well-known song in Am and it replied "Love me to death" by Type O negative, of all things. That's actually in G# minor - interesting the web in general does a really bad job of guessing what key that's in too, most of the responses from a google search say F# major! I'd think "Stairway to heaven" would be about the best known song in A minor - looking at some of the Google results I suspect part of the problem is interpreting the "A" as the indefinite article rather than the note name?)
Does this type of explanation actually help the neural net do anything? If ChatGPT is just combining other instances of A minor music it has been trained on, and has no ability to "understand" what "letters referring to musical notes" actually is, why bother explaining this? Have you tried simply asking it up front to use an am7 chord as the basis for a chord progression or song?
That’s correct. It already knows what “works” musically because it’s likely seen many thousands of harmonic progressions in its training data. The input we give it just constrains it rather than teaching it something new. At least that’s my guess.
