The phrase "a bunch of instruments" is correct and usable in written English.
It can be used informally to refer to a collection or group of instruments, often implying a casual or non-specific quantity.
Example: "The band had a bunch of instruments ready for the performance, including guitars, drums, and keyboards."
Alternatives: "a variety of instruments" or "a collection of instruments".
He had played nearly forty songs from different decades and bands and eras and Zeitgeists, on a bunch of different instruments.
"Just imagine that a bunch of brass instruments are chasing after you," she says, of Horns Surrounding Me. "Then imagine the thing that you are truly afraid of…" The song's threat is muted slightly, by the lack of a touring horn section, but its progression from jazzy unease to full-blown panic benefits greatly live from Fogel clinking the metal bits of his drumkit.
In addition, there are a bunch of musical instruments and artist's peripherals that will connect directly now.
He set up a miniature lab in his two-car garage in Pittsburg, Calif.: a wet chemistry setup and a bunch of measuring instruments including scales, sizing screens (some he built himself) and other lab equipment he scavenged from auctions.
So you give me a studio with a bunch of live instruments, I can do it.
He lives in Los Angeles with a few loud kids, a good woman, a needy dog, some vinyl, and a bunch of acoustic instruments.
She learned a bunch of analog instruments, engineered them herself, and sharpened her electronic production chops to make some of the more ambitious sounds.
There are a whole bunch of instruments I'd like to build.
In Dromgoole's touring production of Hamlet, Laura Forrest-Hay's deliberately anachronistic score features a rustic mix of medieval crusade songs, ghostly sound effects and 16th- and 17th-century Scandinavian folksongs, arranged for a ragtag bunch of instruments: modern saxophone and acoustic guitar, accordion, fiddle and percussion.
At one point she put up a slide of herself in a steamroller, flattening a bunch of busted brass instruments, for her ghost orchestra piece.
