With many apologies on my tardiness (inexcusable, as I am the proud owner of several well-used volumes in this series) I would like to highly recommend Nico Castel's Complete Libretti Series. These books feature complete line-by-line literal and idiomatic translations and IPA transcriptions of entire operas and are an invaluable resource for anyone venturing into the field of opera, whether singer, pianist/coach, or conductor.
The series includes the following volumes:
- The Complete Puccini Libretti (2 volumes)
- The Complete Verdi Libretti (4 volumes)
- The Libretti of Mozart's Completed Operas (2 volumes)
- French Opera Libretti (3 volumes)
- Belcanto Opera Libretti (3 volumes)
- Italian Verismo Opera Libretti
- Four Strauss Opera Libretti
- Wagner's "Der Ring des Nibelungen"
- German Miscellaneous Opera Libretti
- Wagner: The Big Three
They ain't cheap, but if you consider the breadth of information in each volume, they're actually a bargain for the money, and compiled by Nico Castel himself, the world's leading expert on lyric diction.