Speaking personally, I enjoy learning songs that aren't necessarily a predictable "1,4,5,1" progression....but I also like for everyone to learn a song BEFORE going into rehearsal. Practice is to put something together and polish it, not go through the chords and LEARN it from scratch. This requires discipline and structure.....and I realize many "musicians" aren't made this way. To use a "classical music" example.....when an orchestra gets together, the players are expected to KNOW the music before they come in......the conductor then assembles the jigsaw puzzle into the final form. Just my training, I guess.