I'm trying to transcribe a song from a fakebook but I'm stuck on this chord: G-7

Does anyone know whay it is?

G7 chord i think it is G + B + F
I am not sure though hehe

A G 7th chord is the same as a G major chord and a 7th so it would be G B D F. This is how you construct a 7th chord. U need the root, third, fifth, and seventh degrees of whatever scale u're playing in.

Minor correction: if the chord is denoted by a dash following the letter ( as you posted, G-7 ) this usually indicates a minor quality to the chord. Thus, this chord arpeggiated would look like G Bb D F
(1 b3 5 b7)

G-7

G Bb D F

the dash indicates that the chord is minor