Your ability to command fire and bardic music has created a strange blend of both magics.
Benefit: When you cast a bard spell that deals damage, you may replace the spell’s normal damage with fire damage or split the spell’s damage so that half of it is the normal damage type and half is fire damage.
If you cast a summon monster spell as a bard spell, you may choose to give the summoned creature a fiery appearance, which gives it fire resistance 5 and adds +1 fire damage to all of its natural attacks. The creature sheds dim light in a 5-foot radius. This aspect of the feat has no effect if the creature already has the fire subtype.
When you use this feat, the affected spell gains the fire descriptor.