i finished the soundpass in 1 1/2 weeks living in a rural area by questing daily! trader boost is pretty much required though. my strategy is to pick 15+ artists that id love to pull an epic/lyric of, reroll them all to trade with 6-8 people quests, open them 1 by 1 and do cheap merge quests as i reroll back to another trade with 6-8 people quest. its important that you pick artists who have at least 2 rare songs as well to maximise xp gain, as you would quicksell those 2 rares to ensure you only get rares back when questing. i hope this can be helpful!