Ballad of the Battle of Katar

 When you first cast a Ballad, you begin playing a song which contains several verses.  You determine the order in which the song goes through the verses, and a verse may be sung repeatedly on subsequent turns.  However, each Ballad must begin on verse 1 and ends after you sing the final verse.  Each verse (aside from the triggering verse which requires Casting Time) requires an action to sing, and if you ever don't use your action to sing the verse, the spell ends imediately.  On the turn that you sing another verse, that effect will take effect, either instantaneously or for the duration of the turn.  These effects don't affect creatures that are deafened, incapacitated, petrified, or unconscious.  If you are under water, this spell's range is reduced to 20'.  Another target that is under water is only affected by this spell if they are within 20' of you.

Verse 1: "Into the fray they ran, not knowing it was a trap,"

Effect 1: Roll 1d4.  Whenever you or any of your allies within range that you designate roll initiative, add the result to the total.  Whenever any other creature within range rolls initiative, subtract the result from the total.

Verse 2: "the righteous fought them well, and their strikes were true,"

Effect 2: Roll 1d4.  Whenever you or your allies within range that you designate make an attack roll, add the result to the total.  Whenever you or an ally within range that you designate makes another creature roll a saving throw add the result to the DC for that saving throw.

Verse 3: "the wicked were outmatched, and their blows fell short,"

Effect 3: Roll 1d4.  Whenever a creature attacks you or an ally within range that you designate, subtract the result from the total.  Whenever a creature makes you or an ally within range that you designate roll a saving throw, subtract the total from the result.

Verse 4: "the righteous were swift, and moved with ease,"

Effect 4: Roll 1d4.  You and all your allies gain movement speed equal to 5 times the result.  Additionally, you and all your allies don't provoke opportunity attacks when moving.

Verse 5: "ashamed of their failure, the wicked ran in terror,"

Effect 5: Each hostile creature within range must make a Wisdom saving throw or become frightened of you and all your allies within range for 1d4 minutes.  If more than half their allies have been slain, they make this roll with Disadvantage.

Verse 6: "an unyielding vigor, the righteous held,"

Effect 6: You and each of your allies gain 1d4 + your Charisma(Performance) bonus in temporary hitpoints.

Verse 7: "regret seaped in, as the wicked fell,"

Effect 7: Each hostile creature within range must succeed on a Wisdom saving throw.  On a failed save they take 1d4 psychic damage, or half as much damage on a successful save.

Final Verse: "the righteous stood rejuvenated, a blessing from above."

Final Verse Effect: All allies within range (including yourself) regain 1d4 hit points.