Where I levelled my bard
 

I parsed how many xp messages I got in each zone levelling my bard 1 to 60 -- solo xp messages, group xp messages, and the total of the two. Here they are, sorted from most xp messages to least, and along with what I thought of some of the camps.

The Hole: I had fun eyeball pulling with my Singing Steel helm in some strong groups here. We usually had an enchanter, so after 54 I would catch them with ae snare and let the enchanter cc.

Velketor's Labyrinth: the spiders are good xp solo or with a small group, and the Thurg pot material drops make it an easy zone to check. With faction song you are not kos; never take a faction hit from Velketor the Sorcerer. For a small group, if you find Frenzy open I would take it. SK + Bard meleeing singles was a surprisingly efficient duo here. At ~57 or so your ae snare mostly stops getting resisted and it becomes feasible to ae the bottom floor. You can ae the rest too if you can pull them, but I never did find a way to pull them that I was happy with -- sometimes they get stuck pathing above.

Crystal Caverns, Nagafen's Lair (Sol B), and Droga: these three zones have camps with npcs in the 33-37 range which is perfect: 33 stays blue through level 45, and 37 is the last mob charmable with the mana-free charm. I recommend progressing the zones easiest to hardest, charm killing in pairs. At ~40 you can do geonids at the CC exit; at 42ish do Sol B greater kobolds (run through Sol A to the Sol B zone line marked C, then in Sol B clear towards the areas marked A and B); at 43-45 after you've built up some practice charm killing casters in sol b, you can move to Droga, starting on the bridge to the inner sanctum and clearing down -- eventually you can start nearer the EoE camp and clear it.

Howling Stones: solo you can ae kill at the entrance and the basement and later in the west wing -- bleed any harm touches using charm, and either lull or charm kill the casters to clear the way for ae. It's a fun zone to bring a group to too. Duoing with an enchanter or necro that is reverse charming is notably fun. I found it worthwhile to keep my levi cloak clicked and use an sow pot before zoning in when solo.

Tower of Frozen Shadow: I tried to solo near floor 2 exit but couldn't make it to work due to getting charmed too often. After I levelled past the range I discovered that the third floor seems significantly easier than the second -- 3rd floor seems to be only or almost only warrior npcs. The floor keys aren't soulbound so cr could be an adventure.

Eastern Plains of Karana: the ~11 gnolls by the haunted obelisk (#7 on wiki map) are an easy ae with a nice short pull and usually nobody else around. They do despawn/respawn as undead IIRC on a day/night cycle so you can sometimes lose a kite. Gorge hounds are fine too but you have to keep selos up and you have to run all over to pull. The spiders would be good too if you found them uncamped, but they were popular among non-bards.

Iceclad Ocean: the dervishes around TOFS are tailor made for bard ae (good till the bard is level... ~38?). There are ~26 dervishes around TOFS and roaming nearby, on 6:40 respawns. The area northeast of the gnoll camp is a safe area to kill them.

West Commonlands: you can ae the snakes near Kithicor. You can also lull the caster orcs, and pull out the melee orcs to ae.

CT: if you're mildly twinked and have an EB item you can charm kill the blue pool gators when you are IIRC level 30.

Solusek's Eye (Sol A): most of my soloing in here was charm soloing near the zone line that matches up to Sol B's Guano Collector, marked D on the wiki map.
There is some buggy pathing, and the mobs have a wide range of levels. Grouping in the bar area is a ton of fun though.

The Burning Wood: I aed the area around bees some, but I dislike these long pulls.

I'd think w/ an EB item Kedge would be pretty solid for charm killing.

Kinda wanna go try that now on my paladude.

Good info but kind of all over the place in regards to format, also only included levels with some of the spots.

I saw a bard soloing the ceiling piranhas by Undertow once, not sure how good it was for them. The little I tried soloing Kedge was in the front room, and either I was too low level or there was too much variance in the level of the mobs for it to be good for me. I did a lot of mermaids and seahorses on my enchanter; the reason I didn't return to try them on my bard is because fear is disabled in kedge and I was accustomed to using it when finishing of charm kills especially of healers.

You can swim faster than a snared fish. I think the sharks are mostly green 54+ but it could be fun to try killing them in an ae then charm kill the patriarch room seahorses.