He would hear and sing those songs to others inapprehensible, the celestial music.

他会听也会唱那些人们不能理解的歌曲：,天国的音乐。

耶鲁公开课 - 弥尔顿课程节选

That's where this terminology comes in to play because on iTunes we buy songs.

这就是这个术语的由来,我们在iTunes音乐商店购买歌曲

耶鲁公开课 - 聆听音乐课程节选