Stirring Bard

Defender
When Stirring Bard enters, you take the initiative.
Mantle of Inspiration — {T}: Target creature gains menace and haste until end of turn.

Valor Singer

Combat Inspiration — At the beginning of combat on your turn, target creature you control gets +1/+0 until end of turn.

Rugged Highlands

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {G}.

Insufferable Balladeer

Vicious Mockery — When Insufferable Balladeer enters, target creature an opponent controls can't block this turn. Goad it. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Druid Lyrist

{G}, {T}, Sacrifice Druid Lyrist: Destroy target enchantment.

Inspiring Bard

When Inspiring Bard enters, choose one —
• Bardic Inspiration — Target creature gets +2/+2 until end of turn.
• Song of Rest — You gain 3 life.

Merry Bards

When Merry Bards enters, you may pay {1}. When you do, create a Young Hero Role token attached to target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature has "Whenever this creature attacks, if its toughness is 3 or less, put a +1/+1 counter on it.")

Firbolg Flutist

Enthralling Performance — When Firbolg Flutist enters, gain control of target creature you don't control until end of turn. Untap it. It gains haste and myriad until end of turn. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)

War Horn

Attacking creatures you control get +1/+0.

Siren Song Lyre

Equipped creature has "{2}, {T}: Tap target creature."
Equip {2}

Piper's Melody

Shuffle any number of target creature cards from your graveyard into your library.

Mountain

Trumpet Blast

Attacking creatures get +2/+0 until end of turn.

Wandering Troubadour

At the beginning of your end step, if you had a land enter the battlefield under your control this turn, venture into the dungeon. (Enter the first room or advance to the next room.)