Originally Posted by eddie1261
Can someone please define, in simplest linguistic form, what the #1 chord is with no relativity to a key. #1 of what?
I'll have a go. I think we're probably all, or at least mostly, agreed that Mike's comment was confusing".

BTW, I pretty sure you know the following and have just been confused by Mike's wording.
The use of # to mean 'number' not 'sharp' probably also didn't help.

The Dominant 7 chord is the cornerstone of this.

In any major scale there is just one dominant 7 (V7) chord, it's root is on the fifth note of the scale and it wants strongly to resolve to the root of that scale. If we're in the key of C major, the dominant 7 will be the G7 and the root of the scale will be the CMaj. That V7->I move is very common indeed, precisely because it's such a strong resolution.
One of the consequences of that is that the V7 is also usually often a clue that we're about to resolve and because it's usually V7->I we already know where it's (probably) going.

Mike picked out BassThumper's C7 entry and said that the '#1' (meaning the root of the scale) was F, which is correct for a C7 progression, but BassThumper's chart was showing the notes in the chord not the notes/chords in the scale/progression.

Putting that another way:
BassThumper's table showed C7 contains notes C, E, G, Bb
Mike Halloran says C7 resolves to F.
That's true enough, but is a completely unrelated and confusing statement.

Mike seems sometimes to latch onto something and then fail to see the intended context in which that something was written.

Jazz relative beginner, starting at a much older age than was helpful.
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