> Although sometimes it's high status middlebrow kitsch, such as a lot of opera and light classical music, which is more sentimental than technical.

Are you sure it's more sentimental than technical? Like, with-your-ears sure?

Note that it took something like 140 years for someone to write a tempo fugue using a piano technique in Chopin's 4th Ballade. That is to say-- sentimental composers are as good at hiding their technique as audiences are at missing it.