Melodic Casting( Complete Mage, p. 44)
You can weave your music and magic together into a single perfect voice.
Whenever a Concentration check would be required to cast a spell or use a spell-like ability (such as when you cast defensively or are distracted or injured while casting), you can make a Perform check instead. In addition, you can cast spells and activate magic items by command word or spell completion while using a bardic music ability. Bardic music abilities that require concentration still take a standard action to perform.
A bard can't cast spells or activate magic items by command word or spell completion while using bardic music.