[evilkorn]

What level range are right now? How are you getting exp, group or solo.

Generally it's not worth much to swap mid fight. It's easier to swap with main hand instruments, just hold the item and swap before the song completes. You can get more hp regen mid fight with a lute of the howler, which is somewhat affordable.

Mods help with; hp regen, atk mod, damage shield mod, snare speed, direct damage, resists.

So grouping you might only swap during down time to help with hp regen and just use un modded melee songs. Once you hit 30 you get a pretty good bump in damage from using a drum for chants or if you are safe you can use the aoe songs and mod them for more damage if you don't have mobs mezed near by or otherwise safe from additional agro.

Easiest way I found to swap offhand instruments is to have 4 slots in a 2 column hotbar. Main hand - Offhand
Open bag slot - instrument in a bag slot

Drop the main hand weapon down to the open bag slot, swap the offhand down to the inst, let the song land, put in offhand weap put the inst back, then equip main hand.