For the super-contemporary-sounding-and-composed opera that I have upcoming, I broke down and bought a recording made in 2003. I think it's actually the only one that has been made. I usually NEVER buy recordings until I'm finished learning and memorizing a role-- then just to see how other people did it stylistically, etc. But this time, when I received the score about a month ago, I knew I would have to listen to it to 'see' how it sounded.
The way the score is composed, it's pretty much impossible for me to play anything in the orchestra, just my vocal line (since there are, oh, about 20 notes being played at the same time EVERY BEAT), and the WAY the score is composed is also modern (ie, sometimes there are not 5 lines to the staff...awesome).
The good news- the notes that I thought I would previously have to pull out of thin air- DO have a mild support beneath them, and most likely won't be that hard to figure out in the 'sound-wave' of that particular beat.
The not-so-good-news- the actual entrances (beat-wise) are totally random and I can't (yet) hear a pickup or a 'cue' per se).
All of a sudden- OH, that sounds like a super high soprano, oooops, aaaaand there was the entrance. (2 measures ago).
I don't think I'll be listening to it much before doing a full score breakdown, notes, beats, how many PAGES I have to learn(!), but at least I'm a bit reassured that (hopefully) my brain won't hurt toooo much from learning it all.