This is one of two tracks I most commonly see cited out there in Internetland as the best piece on the juggernaut Chrono Trigger soundtrack. The other one we'll get to in a little bit; I rate that one about as highly as everyone else. This one I rate lower than most.
I think this music is a little overrated because Schala is a little overrated. It's not hard to see her appeal: she's a mysterious and kind-hearted teenage girl trapped in a nightmare by her eldritch monster of a mother. Everything about her character screams "rescue me" and she takes an immediate liking to the mute hero--it's everything teenage boy wish fulfillment dreams on. She was far and away the Ensemble Darkhorse and probably has always been the most popular character in the game (only Glenn/Frog is even close).
(Incidentally, I think the Schala obsession also has a lot to do with the appalling lack of an interesting female playable character in the game. Marle is irritating and useless, Lucca is probably the most asexual female character in RPG history, and Ayla is a slut but she's a cavewoman and you can only run so far with that in your dreams. Schala fills the "I wish SHE was my girlfriend" vacuum that in most other games is filled by more sensible PCs like Rydia, Celes, Paula, Selan, Aeris, etc.)
But if you step back and see Schala for what she is, she's a mid-importance NPC on about the same level as Cyrus or Kino or Tata; but it is clear the writers intended her to be a little more important than that, because after all she gets theme music that kicks more ass than any of the playable characters' theme music save one. Schala is also a little more memorable than those guys because of her sacrificial death in the Ocean Palace, sending the tattered remains of your party to safety. (Although, you remember how I mentioned Shadow was the only PC that ever committed suicide? I actually think if you consider Chrono Trigger alone, there's a strong argument Schala, though not a PC, actively chose to stay in the Ocean Palace and die.)
But. But there is no denying this music is Grade A awesome.