A major 7th chord is created by adding a 7th degree to any major chord. For example, a Cmaj7 chord contains the notes C, E, G and B (1, 3, 5 and 7). Here are some common open major 7th chord shapes.
Cmaj7
Dmaj7
Emaj7
Fmaj7
F#maj7
Gmaj7
Bmaj7
Dbmaj7
Ebmaj7
Abmaj7
Amaj7
Bbmaj7