If a Major 7th chord is 1, 3, 5, and 7, then is there a name for the major chord!
Question: She's right basically, except that the 3rd of a chord is the note that defines whether the chord is major or minor. (There is such a thing as a minor chord with a major 7th, it's usually used as an ending chord -- especially in Jazz.)
Anyway, the chord you are describing would basically sound major...especially if it was used as the tonic chord in a piece in a major key. For one thing, the interval between the 5 and 7 is a major third, so that will give a major sound. (If you added the 9 and still left the 3 out you would basically have a poly chord (G/C), which is often used as a substitute chord for a Major 7th chord.
Remember, the 3rd and the 7th are the main notes that define the character of a chord. Besides the root (of course you need the root), the 3rd and the 7th are enough to dictate the basic harmony. So, by omitting the 3rd, you have made the chord a little ambiguous.
I hope that helps.
Answers: She's right basically, except that the 3rd of a chord is the note that defines whether the chord is major or minor. (There is such a thing as a minor chord with a major 7th, it's usually used as an ending chord -- especially in Jazz.)
Anyway, the chord you are describing would basically sound major...especially if it was used as the tonic chord in a piece in a major key. For one thing, the interval between the 5 and 7 is a major third, so that will give a major sound. (If you added the 9 and still left the 3 out you would basically have a poly chord (G/C), which is often used as a substitute chord for a Major 7th chord.
Remember, the 3rd and the 7th are the main notes that define the character of a chord. Besides the root (of course you need the root), the 3rd and the 7th are enough to dictate the basic harmony. So, by omitting the 3rd, you have made the chord a little ambiguous.
I hope that helps.
it's still a Major 7 chord, just with the 3rd left out. :)