First, you need to learn how to play thirteen different chords. These thirteen chords are are: A major, A minor, A major 7, A 7, B minor, Bbdim, C # minor, D major, D major 7, Ddim, E major, E major 6 and F # minor. If you observe closely, the song is changing from the first scale of A to the last scale of D. You will be moving your fingers to eight white keys and it is an extremely simple task.
The first synth sound of the telephone starts from A minor, G major, F major and G major. Then you start the verse. The verse starts with an A major and A major 7. Then you move to Bbdim and B minor. Now play E major, B minor and C # minor. The last line of the first verse finishes with a D major, E major, A major 7 and D major 7.
Start from the part where he says “Hey – How you feelin’,” and you play an A major chord along with an A major 7; keep playing the same chord. Then you kick in with the Bbdim, B minor and an E major. Move back to the B minor chord and then play a C # minor. This part finishes with a D major, E major, A major 7, D major 7, A major 7 and a D major 7 when he is saying “oh!’
All the verses are using the same chord progression that has been mentioned in step two and step three. Keep going around the same chords so that you get the perfect fit once you are singing it while playing.
The most important part is the chorus and you are supposed to play an A major, an F # minor, a D major, E major 6 and a Ddim in order to finish the song off. The chorus has two lines and they both have the same chord progression.