An artist starts with an idea & ends up with a releasable piece of music/collection of songs. A producer oversees some or all of the process between those two points.
Things I do to help get records finished:
Brainstorm/plan/instigate
Project manage
Wrangling: files, players, studio time, next level snacks
Write a budget
Co-write
Arrange
Recommend players (best in Bay and beyond)
Record full bands at a large commercial studio with vibey gear & a great room
Record individual singers & musicians at a smaller ( & cheaper yay!) project studio, still with great gear
Play guitar
Mix