It seems like either this is a messaging bug or an exploit to avoid attacks. I am playing my zills when three raiders hit melee. They can't seem to attack until my song comes to an end:

You begin an off-key ditty on your copper zills, your skill in your craft showcased in every note.
>l
[Manor House, Kitchen]
No fires burn in the great hearths at either end of the kitchen. Now, they hold only cold ashes and the bitter memories of the once-thriving population that resided here. Thick trestle tables are littered with broken pottery, some upturned against the wall and used as target practice, to judge by the splintered scars and broken arrowheads lodged within. The flagstone floor is marred by sticky brown stains.
You also see a red bear orc raider, a red bear orc raider and a red bear orc raider.
Obvious exits: north, south, west.
>get sabre
You get a deep grey sabre with a supple leather grip from inside your leather backpack.
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The orc raider closes to pole weapon range on you!
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The orc raider closes to pole weapon range on you!
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The orc raider closes to pole weapon range on you!
>feint
You are concentrating too much upon your performance to do that.
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The orc raider closes to melee range on you!
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The orc raider closes to melee range on you!
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The orc raider closes to melee range on you!
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You are concentrating too much upon your performance to do that.
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You are concentrating too much upon your performance to do that.
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You are concentrating too much upon your performance to do that.
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You are concentrating too much upon your performance to do that.
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You are concentrating too much upon your performance to do that.
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You are concentrating too much upon your performance to do that.
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>
You cannot use the copper zills while in combat!
Your song comes to an end.
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The orc raider moves into a position to dodge.
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The orc raider moves into a position to parry.
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* With pathetic timing, a red bear orc raider sweeps low at you. You partially block with a stained leather targe painted with a fierce rat.
[You're solidly balanced and opponent has slight advantage.]
>
Learned: Evasion, Shield Usage, Defending, Light Armor, Chain Armor