Arcane Cantata (3.5e Feat)
From D&D Wiki
 Arcane Cantata [Music]
You can boost the power of your spells with the sound of music.
Prerequisite: Bardic music, Perform 5 ranks
Benefit: When you cast a spell with your bard's spellcasting, you can spend daily uses of your bardic music ability to increase the save DC of the spell cast. Each use you spend gives a +1 bonus, and you can spend one use for each 5 ranks you have in the Perform skill.