What do you consider the most musical speakers—$15000 & under

I recently picked up a pair of humble Vandersteen 1ci and they're far more musical than any Harbeth I've heard.

many choices for the above budget. Several great ones already mentioned. Depending on the gear, room etc one can end up with diffrent set-up, inclduing solid state vs. tubes etc and thenmatching speakers will be diffrent. 
Vinatge Altec speakers like the 19, 604 based or Flamenco/Valencia can be great (the latter with legend, Shindo, Air Tight, Trafomatic, Almarro, etc etc gear) or Devore O/93 or O/96 can work really nicely. 
KEF 107 or ADS 1590, Merlin (now out of business), ProAc, Audio Physic Virgo could be awesome for practically nothing with modern or vintage solid state...and then many modern speakers some folks already mentioned. The Vandy Quattro and Treo (perhaps with Vandy subs) is a great choice to my eras for much less than the above budget. Pretty good customer service too. No affiliation with any of these speakers just some experience with 55 or so pairs and many audio friends with diffrent gear and room.

FWIW, my taste runs to the "musical" side of things. My next speakers will be the Devore Gibbon X, which goes for just over $15k. The new Super 9 is less expensive and still great. The Devore room with the new 9 was my favorite room at RMAF 2017 and I hit almost every room (geeked out for 2 days).

As others have mentioned, Harbeth and the Vandy Quatros are also great. Daedalus' new Apollo is also worth a listen for a very musical speaker.

While not generally placed in the "musical" camp, I have owned Aerial Model 9s for over ten years and really love them. Every time I consider new speakers, I can't pull the trigger. What I love about them is that all styles of music sound great and every upgrade in electronics or cabling or power filtering can be clearly heard. For your purposes, you may want to consider the newish 7t which is an upgrade from the 9.

At your price point, I doubt you can go wrong. Have fun.

@helomech I am a long time Vandersteen owner (2C, 3, 3A, 3A Sig.) now Treo CT with two 2wq subs. When I was picking up the Treo’s at John Rutan’s Audio Connection, he played Doug McLeod on Vandy 1C’s. I never would have imagined that RV’s most humble offering could sound like that! Fantastic stuff. If you feed them a clean signal you are in for a real treat.😀

It's strange to me as RV is all about making a great sounding product that hits above it's price.  He even does that his 
Treo CT on up.  It's pretty amazing as I audition them all the time and I audition others all the time.  I honestly haven't heard anything twice the price that I personally would buy.  They are extended and not bright like so many others.  I would listen to a bunch of the speakers talked about here and see what you love.  They all have a different taste if you would, so it's important to hear them.  I have the Quatro and honestly, I may even get a pair of the Sub 9's.  I just like the ability to tune the bass to the room.