Question: What are dominant 7th's and is it the same as a major 7th chord?
Learning chords may seem tricky and confusing, especially for beginners. Don't despair, once you understand how these chords are related and their respective patterns, you'll see that chords aren't so hard to learn after all.
Answer: A dominant 7th uses the symbol of a note name + 7. For example: C7, D7, E7, etc. It is different from the symbol used for a major 7th which is maj7. A dominant 7th is not the same as a major 7th chord. But, to form a dominant 7th you must know how to form a major 7th chord first because these two types of chords are related.
A major 7th chord is formed by playing the root (1st) + 3rd + 5th + 7th notes of a major scale. A dominant 7th is formed by simply lowering the 7th note a half step.
As an example, Cmaj7 = C - E - G - B (7th note). Lower the 7th note a half step, from B to Bb, thus Dominant 7th = C - E - G - Bb.
Here are the dominant 7th chords in every key:
C7 = C - E - G - Bb
D7 = D - F# - A - C
E7 = E - G# - B - D
F7 = F - A - C - Eb
G7 = G - B - D - F
A7 = A - C# - E - G
B7 = B - D# - F# - A
C#7 = C# - E# (F) - G# - B
Db7 = Db - F - Ab - B
Eb7 = Eb - G - Bb - Db
F#7 = F# - A# - C# - E
Gb7 = Gb - Bb - Db - E
Ab7 = Ab - C - Eb - Gb
Bb7 = Bb - D - F - Ab