What are the functions of music in twelfth night?

Music in Twelfth Night is used mainly to portray the mood of charaters in the play. In Act i for example we see Duke Orsino using music to soothe and nurse his pains born as result of Lady Olivia's constant rejection. Music is also used to reveal the inner feelings of charaters. We get to know their state of mind through the kind of music played. For instance we can tell that Orsino is hurting inside and he endevours so hard to put aside his feelings for Lady Olivia, though he can't. He instead continues to pine away with his obsession for Olivia.