Lady GaGa wrote all of the music on her album and plays some of the instruments.

VOA: special.2009.02.27

And you went ahead and worked with the Listening Exercises nine through eleven to engage the musical instruments a bit in those particular exercises, and we have performers here today that are going to, as you can see, demonstrate some of these instruments for us.

你们先前做过,听力练习九至十一题,在这些练习中,你们增长了对乐器的一些认识,今天我们请来了表演者,你们将看到,他们稍候,将为我们在这里演示一些乐器

耶鲁公开课 - 聆听音乐课程节选