Seventh chord vs. Major Seventh chord

If you are confused between the two different kind of chords, here is an end to your confusions. Both chords have three notes in common but there is a different fourth note in both chords.

The formula for Seventh chord is 1-3-5-b7

So a C7 chord will be formed by C-E-G-Bb  notes.

The formula for Major Seventh chord is 1-3-5-7

So a Cmaj7 chord will be formed by C-E-G-B notes.

Although they look similar but they are totally different sounding chords. Try them out and you will instantly know the colour of each chord. 

Now lets talk about a minor seventh chord. What would be it's formula?

Well it is 1-b3-5-b7.

So what will be a Cmin7 chord?

That is C-Eb-G-Bb.

And what about a minor major seventh chord?

That is given by 1-b3-5-7

Cmin(maj7) has the notes: C-Eb-G-B  (This chord may sound weird to some of you)

Play each chord and try to capture permanently the sound of each chord in your brain. These chords are much more colourful than the normal major or minor chords (triads). These can be used to create very deep and strong situations in music.