Issue Checklist

• I have read the Contributing Guide
• I have checked the Issues/Discussions pages to see if my enhancement has already been suggested
• I have properly titled my enhancement

What is your suggestion, and why should it be implemented?

Volumes of the instrumental and vocals should apply to playtest mode. This can be pretty useful for testing how charts will look in-game while also seeing if they properly sync to the music since it can be hard to tell with the instrumental at full volume. It can also just be used for fun; I can personally see myself playing with no instrumental every once in a while for no particular reason.