Whether you call them instrumental tracks, playback, rehearsal tracks, or simply backing tracks, background music tracks are important to singers at all levels.
Everyone knows about the huge influence the city of Nashville has on the local and international music scene, and not just for the Country genre.
Are you familiar with "the lips, the teeth, the tip of the tongue" tongue twister? If you've watched the comical movie "School of Rock" with Jack Black, you'd probably realize that it's a vocal warmup technique but it's so much more.