When writing a song it is good to look at the arrangement.
how many bars of what for how long
16 bars of 4/4 at 120 bpm = 32seconds
8 bars of 4/4 at 60 bpm = 32 seconds
4 bars of 44/ at 120 bpm= 8 seconds
How many bars will you cover in Minute at 120 bpm
Let's make a song with a verse and chorus!
How long do we and the verse to be?
How long do we want the chorus to be?
Once you have decided these two sections, now choose your chords.