I very much enjoyed The Ghosts of Versailles
by John Corigliano. I once had a video of the Met production, with, among others, Teresa Stratas, Renee Fleming and Marylyn Horne, but I'm not sure if it was made available on DVD.
I note you ask about the operas of Holst and RVW. The English National Opera recently did a production of RVW's Sir John in Love
, which was hugely entertaining, though the opera itself is, inevitably, somewhat inferior to Verdi's treatment of the same subject (Falstaff
). I also like Gustav Holst's Savitri
, of which there is a wonderful recording with Dame Janet Baker. I saw it once many years ago, when still a teenager, coupled with Menotti's The Old Maid and The Thief
. It cast quite a spell on me, but I can't remember a thing about the Menotti.
I have a CD of excerpts from Walton's Troilus and Cressida
, with Schwarzopf as Cressida. Walton originally wanted Callas, but she showed little enthusiasm for 20th century music (not even for Puccini) and declined, so he wrote the role with Schwarzkopf in mind. I'm not sure why, but she never ended up singing it on stage and the premiere went to Magda Laszlo, though Schwarzkopf did agree to record these excerpts. It is a gloriously lyrical and romantic score, and well worth hearing. Later on Walton transcribed the role of Cressida for mezzo, so that Janet Baker could sing it, and there is indeed a complete recording of this version with Baker, though many critics have found it less successful than the soprano version, which was eventually recorded with Judith Howarth and is now available on Chandos.