So looking through the Faction Guide there is a resource under "The Ninth Battalion" (pg32) that grants this bardic performance:
“The Summer Axe of Kotzranj Yar.” When a bard sings this, he and his allies increase the critical threat range of their melee weapons by 1 (from 20 to 19–20, from 19–20 to 18–20, and so on). At bard level 11, the critical threat range increases by 2. This effect does not stack other effects that increase a weapon’s critical threat range.
And the Feats "Grand Master Performer" (pg56) and "Master Performer" (pg57) that both state "When any of your bardic performance abilities
grant your allies a bonus, that bonus is increased by +1." And they state the two feats stack together.
Now, Unlike the Keen weapon enhancement or the Improved Critical feat, which double the threat range of a weapon, this performance increases or adds to the existing crit range.
So my question is this: Would the above bardic performance be affected by these feats?
Nope, the performance does not grant a bonus, hence it is not affected by those feats.
Bonuses are numerical values that are added to checks and statistical scores.
Thanks. They really need to fix the Faction Guide. There is some cool stuff in there, but they have too little information and poor wording on most of it.
Still available via Paizo, though! I got a 'non-Mint' version that seemed very close to mint. Great book, IMO. 25% off, even! (/Snagglepuss impersonation)