Bard question for dungeons

Hi
I've recently finished the story and have just started some of the lower level hard mode dungeons. My question is about singing. I've always used mage ballad when I see the healer is getting low on hit points.
My question is should I be using foe requiem regularly now and should I use it on all pulls when my mp are up?
I had a scolar ask me to use it in AK and we had me a dragoon and a tank so I assume the scholar wanted to damage. I run regularly with a dragoon so is it worth it for four man's without a SMN or BLM?
Thanks I'm still learning and want to do the best I can for the group.

Use it when you can see the healer/healers actually dealing damage; otherwise there's no point. So many times I've had Foe's up without the healers dealin' damage - not worth the MP.

However obviously for example, if you've got a BLM or SMN then use it as much as you want! But keep in mind how long you have it up incase you'll need to use MB or AP.

Sing ballad between pulls if the healer was holy spamming. Sing it if they were rezzed during a boss fight. For trial fights you may need to sing if a lot of rezzes were going out or a healer dies.

Sing foe every pull you have mana for if the other dps is a caster. If tank is mass pulling for aoe always use foe if you have a caster. If other dps is a bard or melee then sing Army's Peon for aoe pulls.

Get Invigorate ASAP. Thank me later.

Thank you :) and yes I already have invigorate, very useful.