butchblack
Life is short. Do good. Find and do what you love.
If we played dance venues, we used to extend the shortest songs out to at least 5 minutes to keep the crowd dancing.
Our basic formula was:
9 songs x 5 min. = 45 min. per set
Some songs were longer so we sometimes played 8 songs per set. With short breaks between the songs, we played 4 hour gigs with around 35-40 songs.
Most of what we were playing were songs with a set pattern, other then maybe extending a solo an extra 12 we weren't set up for it. And using your formula our 1 hr sets had 12 songs. 12 songs x 5 min. = 60 min. set
With a new guitarist coming in with more of a 70's blues rock background I hope we'll put in some material that lends itself to a longer jam. We got caught flat footed once, underestimated the time of a set and started the last song and then realized that we had about 15 minutes left. We stretched that song for about 10 min. A couple good jam songs would have saved the day.