What is the ruling on a vow that entails fasting three days, praying two rak'ahs, and giving charity for every song heard, taking into consideration not remembering the number of the poor, and does this vow continue for every song heard in the future after repentance?

The scholars disliked making vows (nadhr) in advance. The essence of a vow is to be an act of righteousness and drawing closer to Allah. However, if it is made as a means of pressure or deterrence, it is called a "vow of obstinacy" (nadhr al-lajaj), and the one who made it has the choice between fulfilling it or offering an expiation for an oath (kaffarat yamin). If you vowed to abstain from music, you have the choice between fulfilling the vow or offering an expiation for an oath, which is: feeding ten needy persons, or clothing them, or emancipating a slave. If you are unable to do that, then fasting for three days. If your intention was for it to be repetitive, then you must offer expiation every time you listen to music or do what you vowed against.