I mean, you could make sigils to help certain things such as helping you stay motivated to practice. As a fellow musician, however, no matter what sigil you use you won't improve if you don't practice. Sigils would probably work best if used to help your practice be more mindful or productive.
If you believe that sigil magic will help you to become a better musician, then I say yes! Keep in mind that You are also responsible for making yourself better at it by practicing and really applying yourself. Counting on magic alone (sigil or otherwise) won't do it. You also need to put in effort and do your fair share!
Being attractive and being a better musician are very different things. If you meant one, why did you ask about something completely different?
As for changing your physical attractiveness, magic can help you with things such as determination and the like, as stated above. But no magic can change your physical appearance.
An adendum is the concept of the Glamour, which is a category of magic which causes people to perceive you differently. A great example can be seen in Marilyn Monroe:
There's a tale from someone who was taking a walk with her in New York City for an interview. Nobody seemed to notice they were passing such a massive celebrity, and Marilyn even cited as much, saying how she can't do the same in Los Angeles; too many people would recognize her, even in her every-day type of clothes, blue jeans and a plain looking top. But she turned to her interviewer with a coy expression, and asked, "Do you want to see me become her?" Uncertain what she meant, Marilyn changed her posture and facial expression. Suddenly, other pedestrians gawked, drivers stopped in the street to shout to her, all recognizing her for who she was. A glamour does not change a person's appearance, but it absolutely changes the way a person is perceived. I think, if you're wanting to become famous and recognizable, this may be the direction you wish to look.
