What is the ruling on someone who repents a general repentance from sins, but makes an exception for some of them, such as listening to music? Is his repentance accepted for apostasy and the sins he rep repented from, or does the entire repentance become void due to that exception?

According to the Sunnis, repentance for some sins is valid without repenting for others, unlike the Mu'tazilah. So, if someone makes a general repentance, their repentance is valid for all sins except for a specific sin they did not repent from, such as if their desire for it is strong or they believe it to be good.