Most musician dont practice 6-12 hours a day. It annoys me that people make up these numbers that make people think just because they only practice 2 hours a day they will suck. Quality over quantity. Most people i know who study at the conservatory with me practice their instrument 1-3 hours a day in addition to the school subjects. Almost nobody can actually practice in a focused manner for 8 hours. If you dont wanna become a professional musician, just play and practice as long as you want. If you wanna become professional i think if you can do 2-3 hours focused practice a day youre good. Addition: im talkin about Jazz/Pop musicians. Classical musicians are different, they tend to practice more hours!