copy paste from the post I made on PEQ's forums:
Implementing Bard AAs: Improved Instrument Mastery, Improved Singing Mastery, and Echo of Taelosia
in zone/client_mods.cpp lines 1510 - 1514
	Code:
		if(spells[spell_id].skill == SINGING)
		effectmod += 2*GetAA(aaSingingMastery);
	else
		effectmod += 2*GetAA(aaInstrumentMastery);
	effectmod += 2*GetAA(aaAyonaesTutelage); //singing & instruments
 change it to
	Code:
		if(spells[spell_id].skill == SINGING)
	{
		effectmod += 2*GetAA(aaSingingMastery);
		effectmod += 2*GetAA(aaImprovedSingingMastery);
	}
	else
	{
		effectmod += 2*GetAA(aaInstrumentMastery);
		effectmod += 2*GetAA(aaImprovedInstrumentMastery);
	}
	effectmod += 2*GetAA(aaAyonaesTutelage); //singing & instruments
	effectmod += 2*GetAA(aaEchoofTaelosia); //singing & instruments
 I just did 2*GetAA because that's what all the other AAs had, tested and worked on my server