score:5
Is it ok to use music to induce positive states of mind, especially to uplift one's mood and alleviate depression?
Yes, if you are a layman and if you are not observing the 8 precepts.
If music can be used to uplift one's mood, then why is it considered unwholesome and against the seventh precept?
'Uplifting' here means inducing pleasurable thoughts/feelings. Even Marjuana can do that. Some people eat sweets to uplift themselves. Uplifting doesn't mean wholesome. It's important to note that hearing music by chance does not break the precept. Listening intently breaks the precept.
How does music cause attachment or craving?
Music is sound that is pleasurable. Wanting to hear pleasurable sounds is a sign of craving.