Laurence Rosenthal composed the Young Indiana Jones theme used in the television broadcast opening credits and was also the primary composer for the show, scoring and conducting the music for just under half of the episodes. Rosenthal's website lists the awards he won for the series and contains several sample tracks for listening. Additionally, in 2009, film score journalist Jon Burlingame conducted a three hour interview with Laurence Rosenthal discussing his film and television work. At 2:12:04, Rosenthal speaks for ten minutes about his scores for Young Indiana Jones. Highlights include:
John Williams originally recommended Laurence Rosenthal to George Lucas
Curse of the Jackal was originally temp-tracked and recorded with the Skywalker Symphony Orchestra
The rest of the series was recorded with a 55-piece orchestra in Munich, Prague, Budapest, or Australia
Rosenthal's favorite scores include Vienna, 1908, Peking, 1910, and Istanbul, 1918
Joel McNeely was the second primary composer hired to score the music for Young Indiana Jones. McNeely's website includes extensive samples of his music from various episodes. Apparently, McNeely had also composed a main theme for the series, but it was never used. Over the years, McNeely has shared an extensive amount of behind the scenes information regarding his work on Young Indy in many different interviews. These include: the documentary Young Indy Around the World (at 2:57), a magazine article from Film Score Monthly (page 12), an interview published by BSO Spirit, and a podcast episode from Cine Concerts (at 13:29). Highlights include:
Episodes [as aired on TV] had 40 - 45 minutes of music which needed to be composed within two weeks
Ben Burtt usually produced a temp-track with music of the appropriate theme
Sometimes the scores would be written in McNeely's hotel room in Munich before the recording session
McNeely himself played the soprano sax for Indy's performances in Mystery of the Blues!
Frédéric Talgorn composed the score for the Somme, 1916 and Germany, 1916 episodes that were later combined into Trenches of Hell. Talgorn's website and official YouTube channel include extensive samples of music from this episode. In addition, Talgorn discussed his work on Young Indy with author Aaron Lam for his book Composing Adventure. During this interview, Talgorn revealed that he also composed an unused score for Paris, 1908!
Steve Bramson composed the score for Treasure of the Peacock's Eye. He has some samples of music from the episode on his website. Bramson received his masters degree in film scoring at the Eastman School of Music, where he was a fellow student with Joel McNeely and later worked as an orchestrator for Laurence Rosenthal directly out of college. According to the liner notes on the Volume 3 soundtrack CD, Bramson also worked as an orchestrator for Joel McNeely on some of the cues from Mystery of the Blues and The Scandal of 1920. Episode 235 of The IndyCast (at 6:50) features an interview with Bramson, by Mike Jozic, where they discuss scoring the episode in detail.
Curt Sobel composed the chilling score to Transylvania, 1918. Sobel is also an award winning music editor and successful songwriter. His website lists his many accomplishments and credits his work on Young Indiana Jones.
John Williams' iconic "Desert Chase" and "Raiders March" themes from Raiders of the Lost Ark were used in the Mystery of the Blues bookends featuring Harrison Ford. The music was arranged by Joel McNeely with the rest of his score and was all newly recorded for the episode.
David Slonaker & Arthur Kempel are both credited as assistant composers and orchestrators. According to the documentary end credits on the Young Indiana Jones DVD set, Slonaker worked with McNeely on Paris, 1908 and Kempel worked with McNeely on Attack of the Hawkmen.
Other Composers contributed to the series in the form of diegetic music:
Giacomo Puccini, The Perils of Cupid
Wolfgang Amadeus Mozart, Demons of Deception
Johann Sebastian Bach, Oganga: The Giver and Taker of Life
Nikolai Rimsky-Korsakov, Espionage Escapades
Sidney Bechet, Mystery of the Blues
George Gershwin, The Scandal of 1920