I found if you used a mod for vocals you will pass the amount of time for visiting for vocal training don't add vocals till after first concert
Thank you for the hint, but what do you mean by a mod for vocal?
I didn't use a cheat to increase Alex's vocal skills, if that's what you mean.
I used a mod just for the following cheats:
1) change weather
2) add money (but i still work both at the café and at the casino, and I distributed flyers so I got the suspicious package delivery job)
3) change arousal
4) remove hugryness, tiredness, body odour, stress, depression, pain
5) add or remove cum on MC's body
6) increase inspiration
For all the rest I did the grinding.
I just skipped time by the "+2h" command which is built-in.