"music on hold"-grade tune
Refers to a somewhat-"tame"/boring and/or repetitive musical composition that is "okay", but definitely nothing special or "memorable" --- it would merely be something that you might wanna half-listen to while waiting for someone to pick up/get back to you on the phone, be serenaded with over a store's PA system while shopping, or have for soothing your impatience when riding a slow elevator.
The NYC Greyhound station plays light-classical music over the ceiling-speakers to help its patrons to while away the long boring hours during bus-layovers; I appreciate it that they don't simply toss "music on hold"-grade tunes at you for extended periods.