Bard's role in early game and midgame hasn't changed much; it's only the role in endgame that fluctuated dramatically over the last few years.
Your role is one of pure support in most parties. You're generally expected to have BRD/WHM and be able to lob cures and remove status ailments, at the same time buffing members of your party to make them perform better. Your three most important spells will be March (haste song for the melee), Ballad (refresh song for the mages), and Elegy (slow for the monster), with accuracy and regen spells being important too. Later on you'll add in Carols (bar spells), Threnodies (elemental weakness on monsters), and some oddball songs that will help out party members in a pinch at endgame (managing enmity levels, reducing chance of oneshots on NMs that do critical damage, etc.)
Bards may also melee situationally, although that depends on the taste of the bard in question, and if things are going poorly you are generally expected to fall back into a pure support role again. Bards also make excellent pullers for monsters that can be slept, as you can grab a fresh mob and sleep it until it's ready to be hit. (Not used nearly as much today as it was in ye olde colibri parties, but I find myself falling into that pattern for things like dolls out in the desert in Abyssea.)
____________________________FFXI: Catwho on Bismarck. Once again a top bard on the server: Dardaubla 90 on 1/6/2014
FFXIV: Katarh Mest on Lamia - Member of The Swarm and leader of Grammarian Tea House chat LS
I can't understand anyone who skips the cutscenes of a Final Fantasy game. That's like going to Texas and not getting barbecue.