。
She married a musician.
Literal
She [topic-は] musician [with-と] married.
結婚する takes と (not を) to mark the spouse — Japanese frames marriage as a joint act with a partner, not an action performed on them. This comitative と pattern shows up in many verbs of mutual action: 話す (talk with), 喧嘩する (fight with), 相談する (consult with). Note also that there's no article distinction in Japanese: 音楽家 could be 'a musician' or 'the musician' depending on shared context.