Only a bit - bards don't have stealth ability.
If they had, they would be powerful.
But they DO have a backstab.

Bards can cast one level 3 spell at level 7 (2 at level 10). AFAIK their song and their spell should affect summoned creatures. I don't see why not, but I don't usually bother with the tactic, so if someone else knows better, then please inform the ignorant amongst us!

Bards are versatile; not having backstab is a minor annoyance. If you search on this board you'll see many debates that extoll the virtues of the mage and how their abilities can compensate (if not improve upon) a thief's abilities. In fact, the only thing that spells in BG cannot improvise is pick pockets, and bards get that anyway.

A half dozen or so ogres and a few Hobgoblins backed with a singing spectre (Invisible bard singing) was enough to wear down Saravok and his cronies. In the end, Saravok fell to a fatal flung axe blow to the head.

Summoned monsters and bard song will chew through most anything in the game.

for vanilla bg i can see a bard managing it and completing all quests too, but durlags tower and aec'letec is a tougher proposal or even ww island, anyone managed that?

I didn't take the time to read each and every reply, but I did read about half of them, and here's my two cents. My first solo ever was a Bard. I used bows and longswords(Eagle Bow and Varscona). I had on the Bracers AC:6, a RoP +2, Boots of Speed, Girdle of Piercing, and don't remember much else. But one thing I do remember is using Algernon's Cloak A LOT. Now that I think about it, I'm gonna start up another one tonight and see how it goes.

Actually, from what i read in this thread, bards do have a backstab multiplier.