What I find odd is the save DCs are 8 + prof bonus + ability bonus. It makes it less smooth, but I realize they probably want to reign in some of those save DCs for characters without prof bonuses to their saves.
My thoughts on the Bard so far:
-It seems like the Bard is the only class with only 4 ability increases/feats. They need to change that, as it was my criticism of every class that had only 4 last session.
-Bardic music only once per encounter, and you can't choose a different one later in the encounter if you stop performing, seems simple enough. Also I noticed the refresh is after 10 minutes, but a short rest is still 1 hour.
-So far the Bard Colleges are good for a core Bard, but I feel there needs to be a bit more variance between them. One of them would be a more spellcastery Bard, could be something that should be toyed with.
-I miss the ability to use Suggestion on fascinated targets with Bardic music, the College of Wit really needs that brought back from the old Bard abilities.
-Save profs of Intelligence and Charisma, I feel there's a problem with those 2 saves since they're so far the less commonly used ones. Granted Bards should be proficient in Charisma saves. That leaves Int saves. I think it might be better if different subclasses grant a different secondary save prof.
-I miss Bards getting 6th level spells, I know that being half casters is appropriate for most cases of the Bard, but some could be 3/4 or maybe full casters.
-"Implements", I don't approve of only musical instruments offering spellcasting bonuses. What if the Bard is a vocalist or a dancer? I think at least wands should be added. And doesn't that just make it odd for College of Valor Bards, with a sword in one hand and a lute in the other.
-Countercharm, Improved Dispel and Jack of All Trades I approve of. Battle magic is good, but it's something I feel could also be College of Valor only, if something is needed to make other colleges have more options to input later.
-The extra dice of damage for Call to Battle is probably easier to remember than, +2 I had to call out for the Inspire Courage all the time when I played one.
- Magical Secrets is something I feel a Bard should get at a lower level, starting with just 1 new non-bard spell learned, and gaining more as the Bard levels up.
-College of Valor is good Bardic version of a Warlord, but I feel if any subclass of the Bard deserves a d8 hit die, it's that one.
-Song of Rest is something I feel could be moved the the greater Bard class.
-I don't think the last abilities of both subclasses should be a free spell known, plus a free casting. I feel it should be another bardic music use, though maybe something that only happens once per performance.