It hasn't happened yet but I keep threatening to craft a Gong bard. I just so badly want a Dwarven Bard who carries a full size gong on his back. Just salty, hateful and thwacking a Gong angrily. Its such a beautiful idea. Haven't had the chance since I came up with it. I usually Dm so it will have to wait.
Not that exotic, but I tried to stick to PHB instruments to keep the cost fair at level 1...but with a bit of a twist. Mandolin (instead of lute), recorder (instead of flute), cowbell (bell from the equipment list), and wooden xylophone (basically a pan flute played on its side as percussion). In real life I bought a recorder, xylophone, and cowbell on Amazon all for less than $30 and I've been torturing my group with horrible music and parodies for months now (I'm not much of a musician).
In game, If I get a chance, I want to mount a hand crossbow under the mandolin...the DnD equivalent of Antonio Banderas's Desperado.
Strength was my dump stat, but we found some gauntlets of ogre power. Somehow I ended up with them which sparked a debate about whether they counted as heavy armor and whether they would affect my ability to play the instruments. My solution was to stick with the cowbell, which I can now simply tap with my gauntlet-covered finger. My GM allowed it.
I'd prefer to keep things simple. 1 string instrument. 1 wind instrument. 1 percussion instrument. The more portable the better.
Apply prestigination (sp?) to tune the instrument to sound exactly as you want it to. That lute can sound like a banjo or an electric guitar. A halfling with a harmonica belting out a classic bagpipe song...why not. There really is no reason why that little Fisher-Price looking xylophone can't sound like a massive drum kit.
I made a strong, rather dumb (human) bard (13 strength and 9 intelligence) and gave her: a lyre, a (Djembe) drum, and bagpipes. since she's not so bright, I thought she could use one of her instruments as a weapon And I showed her off to my friend and told them that. And they said, AND I QUOTE: 'Her music inspires bravery in her allies and her brutal bagpipe attack inspires fear in her enemies'
I have a flute, just because technically he's a bard. However, I roleplay him to be a combat tactician that exposes flaws in the enemies' defenses etc. He shouts commands and infos. He's a very brainy bard, knows a lot of monster lore and also can exploit weaknesses himself by using his bardic inspiration as attack (he's a Whisper Bard). He uses material components for spells instead of his flute, and for song of rest he basically makes a debriefing of previous encounters and what to do best next time.
That said, he's a 2ft small furball that's super cute and people have a hard time taking him seriously, because he looks so adorable. I use bard because I like the mechanics for the inspiration and song of rest in the context of his liberal interpretation of performance. He's a bit like a teacher/coach.