Steps:
1. Paint lamp base with spray paint in a well ventilated area. (Preferably outside.) Let dry thoroughly.
2. Make 2 color copies of sheet music.
3. Place music copies on lamp shade and trace lamp shade edges with pencil. 
Cut at traced edges.
4. Glue music copies onto lamp shade in patchwork fashion using decoupage glue and disposable brush. Let dry.

Note: Remember that a project using copyrighted items cannot be legally sold by the individual.... for example in fund raisers or flea markets or retail stores.