Hello!
As the title suggests, I'd like to suggest changing Lingering Song (Which sucks as it is, now) to a similar mechanic to the Acolyte or Apprentice aspects. 1 song regenerated per 10 minutes.
As per those aspects, it'd help a bard who's willing to pay the feat tax to stay relevant in long events or very long quests, without directly effecting pvp or normal quest balance.
Cheers!