Soul Voice
From Final Fantasy Wiki
Soul Voice is the Final Fantasy XI Bard's Two-hour ability. Soul Voice lasts for a period of three minutes, unlike most of the two hour abilities available to other jobs which are instant or last for 30 seconds. This is largely due to the time involved in singing songs, which is generally between 3 and 8 seconds. A bard might also be responsible for singing as many as a dozen songs in certain party combinations.
During the period when the special ability is active, any songs a bard sings will have an "increased effect," as the game puts it. While this is not exact, in most cases, this means the effect of a song is doubled (IE: Foe Requiem VI, which normally would do 6HP of damage ever 3 seconds, would do 12, or if Valor's Minuet ordinarily would boost a party member's attack by 25, it would boost it by about 50.) Offensive songs also become more difficult to save against, so they are more likely to effect the target.
