I need to do this country in pieces, starting with music:
Classical guitarist: Segovia, starting with his recordings of Bach. It’s not just amazing technique, these are some of the best musical interpretations of Bach by anyone playing any instrument. They are what I call lifetime choices for one’s collection.
Composer: Varese sounds much better live than on disc. I’ve seen AmÃ¨riques twice and both were experiences to remember; here is a bit on YouTube. Chailly and Boulez understand the music very well but the sounds and textures and rhythms simply don’t all come through if you’re not there. (Addendum: Whoops! Varese was born in France.) The number two pick is tough but Rodrigo is underrated by many serious listeners, in part because of his exposure through classical pops. Try his solo guitar pieces and throughout keep him in mind as a precursor of ambient music. Tomás Luis de Victoria is an underrated Spanish Renaissance composer.
Cellist: It’s hard not to pick Pablo Casals, who had extraordinary depth in his phrasing. I still feel duty bound to point out that most of his recordings are unlistenable, if only because of the scratching. The Bach is of historic importance but for actual pleasure his Schubert is your best bet. Most of all the recording of the String Quintet.
Album about: Miles Davis, Sketches of Spain. One of my three or four favorite Miles CDs, so an easy pick. Admittedly the move toward an "acoustic-electric" sound does not appeal to all jazz fans, so this album remains underappreciated.
Opera singer: Lots of riches. Placido Domingo is a good pick though you could argue for many other names as well.
Popular music: Help!
Flamenco: I love it in small clubs but not on disc or even in mid-sized university music halls.
The bottom line: There are plenty of peaks but overall I am struck by the unbalanced nature of the distribution.