It possible use weapons as percussions instruments for bardic performance

[Atrian]

I was thinking to do this bard, who is the inspiration for his "compositions" are the battles it self.. so he mold his song as the battle progress... the idea is he use the clash of weapons and heavy boots hitting the floor to mark the rhythm of his bardic performance... I do not know if this is possible in term of game mechanic.

[ShieldLawrence]

Bardic Performance doesn't actually require you to use an instrument so I'd say it's super okay.

[lemeres]

Yeah, even if you were restricted to a proper type of performance, there are plenty of methods that don't need you carrying a guitar around.

Song and dance are obvious, but maybe not your flavor. Heck, maybe what you were talking about technically falls under dance (I can imagine a dance routine where rhythmic stopping to the music is a thing, particularly in large group dancing seen in things like musicals).

Comedy works, where you just need to wise crack, but again- that is a particular flavor.

Oration and acting are interesting. You just have to shout some inspiring words. I can easily imagine a kung fu movie where the guy yells something like "the heavens may forgive you, but I shall not!". Under this theory, your performance is just your character actively acting out a character (often seen in things such as a tough bandit or orc warlord shouting and bragging to his opponents; that is a performance to convince his men that he is strong, and that they should follow him).

[My Self]

Considering that the War Drummer Skald (1/2 Bard, 1/2 Barbarian) archetype uses clubs and has a "siege drum" ability that doesn't actually reference the percussion bardic performance, I think you'd be completely within your rights to have a bard that does something like that. A small number of GMs will be a bit stricter on this matter. Regardless, most Perform skills are much more equipment-optimal (Sing, Dance, Comedy, Act, and Oratory can be done without instruments), so you should be fine.

[Mark Carlson 255]

Ask your GM.
MDC

[Wheldrake]

Soldiers smashing their spearshafts against their shields was really a thing. It's been a while since I read it, but IIRC it features in the Illiad, which is one of the earliest literary battlefield references preserved to this day. Surely that could be Perform (percussion).

Perform (oratory) exists. Think about the inspiring speeches in Braveheart. No need for an instrument as such.

Or, get some master smith to craft you a singing sword. <g>

[Azothath]

Yes and no.

In the game weapons are not instruments unless they are specifically designed to be so. DnD is not constrained by reality, just believability. Barbarian campanologists would be amusing. A recorder could double as a short blow gun, but that's the reverse of the premise here.

Physically, big solid blunt things make terrible (percussion) instruments as their ability to resonate in the hearing range is poor to impossible. Instruments generally need an area that acts as a transducer to transmit the physical force of playing to the air. They also need some resonance to create harmonics. If you just need a 'thud' then a club will be okay. It's nice when the game follows physics and what we know as then it lends to believability.
Pianos while big and heavy are made of many parts. The strings vibrate and conduct to other strings via the frame. The sounding board then acts as an amplifier. I don't think pianos are weapons except in cartoons or as siege weapon ammo. So I don't expect to hear, "his clavicle got clavichorded".

A GM could create a 9 chime temple sword, triangle shurikens, tubular bell staff or chiming staff of many parts, cymbals of sharpness(chakram)...