So I'm the only bard who actually swaps instruments and weapons fairly
regularly?

For what it's worth, here are the two ways I do this. (btw, I'm level 13)

Hotkey bank #2

Anthem Hymn
off-hand CoD
El Rhythm Bellow

Either the lute or the drum is equipped and the other's on the cursor which
is kept over the off-hand hotkey. The battle would start with something
like ER, Anthem, equip lute, CoD, equip drum, rinse, repeat. The battle
would end with something like Hymn, Bellow, Anthem all with the lute
equiped.

Swapping weapons to instruments & back again is something I only do when
soloing.

Hotkey bank #1
prime hand off hand - lute
inv 1 - sword inv2 - drum

Shield is on cursor

Hotkey bank #5
Warsong Hymn
Selos CoD
El Rhythm Bellow

I use these banks to switch from a CoD/Hymn/Bellow with lute combo (what I
start the fight with) to a Warsong/Bellow/Hymn combo with sword and sheild
(what I switch to when chasing a fleeing mob) to a Selo's/Hymn with drum
combo (for getting back to safety). I change to sword and sheild between
Warsong and Bellow and change to drum after hitting Selo's.

But then what do I know I'm only level 13. :-)

Peace
Evulia of Tunare