The term backline used to refer just to audio amplification equipment that stands behind the band on stage, including amplifiers for guitars, bass guitars and keyboards. In the US, backline has expanded in recent years to include the instruments that the musicians play, from guitars and bass guitars, to keyboards and organs, to drum kits and various percussion instruments.

Memory control circuit for optimizing copy back/line fill operation in a copy back cache system
Evaluation of a deltamethrin formulation as a back-line treatment of sheep for the control of the sheep body louse (Damalinia ovis)
Physical model of back line-contact front-junction solar cells
Analysis to the Status Que of Back Line Offence of China Woman Volleyball Team in the 9th World Cup Woman Volleyball Competition
Residues in cattle tissues following back-line and spray applications of trichlorfon
Fabregas the Key to Unlocking United's Back Line ; in the Absence of Van Persie and Arshavin, the Spaniard Must Be Used in an Advanc...
The evolvement and practice of the back-line defensive tactic in modern volleyball games
Comparative Analysis on Men's Volleyball Back-line Attack Home and Abroad
Mode of action of back-line application of spinosad, a non-systemic parasiticide, on sheep.
Shoe back line press