。
She always studies while listening to music.
Literal
She [topic-は] always music [object-を] listen-to [while-ながら] studies.
~ながら attaches to a verb's masu-stem to express two simultaneous actions performed by the same subject: 聴き (from 聴く) + ながら + 勉強する gives 'study while listening.' The order encodes a hierarchy — the main verb (勉強する) is the primary action, the ながら clause (聴きながら) is the background. 聴く is the deliberate-listening kanji as opposed to the more general 聞く; here the choice fits 'studying with music on' more precisely.