Leoncavallo, Ruggiero: Biography outlining major successes and failures and noting his pioneering work in phonographic recording. From the Grove Concise Dictionary of Music entry at WQXR radio.
Ruggero Leoncavallo: Discussion of his place among operatic composers, especially his influence on verisimo. Includes photo and summary of his works.
Ruggero Leoncavallo: Filmography at IMDb lists writing and music credits for various movies and television shows using his compositions. Most are various performances of or borrowings from I Pagliacci.
Ruggero Leoncavallo: Find A Grave listing with birth and death dates, biography, cemetery information, and interactive memorial.
Ruggero Leoncavallo (1857 - 1919): Karadar dictionary entry with life, portraits and caricature, related composers, and listing of operas and operettas including the Italian libretto to I Pagliacci.
Ruggero Leoncavallo (1857-1919): Brief biographical sketch, caricature, summary of operatic works, and Naxos discography.
Ruggiero Leoncavallo: Wikipedia article with biography, lists of operas and operettas, and internal references to related people and topics.
Ruggiero Leoncavallo: Entry at the Lied and Art Songs Text Page with list of vocal works and selected lyrics.