the.com/chamber pop

means A style of pop/rock that layers in orchestral, classical-leaning instrumentation — strings, piano, woodwinds — for a lush, intimate sound instead of straightforward guitars-bass-drums.

from The 'chamber' comes straight from 'chamber music,' the classical tradition of small-ensemble pieces meant for intimate rooms rather than concert halls. Bands in the indie-rock scene of the 1990s and 2000s borrowed that instrumentation — cellos, violins, horns — and the name followed naturally, marking the genre as pop that had traded arena bombast for something closer to a parlor recital.