That's "Bix" Beiderbecke, born 108 years ago today in Davemport, Iowa.
It's possible Lombard didn't see Bix's name on those records, as most of his time was spent placing cornet for some of the best-known bands of the day, such as Paul Whiteman's. But Bix was renowned for his mastery of music; he and contemporary Louis Armstrong added to the depth and texture of jazz. (Beiderbecke and Armstrong knew each other, but I don't believe they ever recorded together -- first, they approached music from substantially different directions, and in those days, integrated recordings were rare.)
Bix was an accomplished musician who also excelled on the piano and even wrote a few pieces for the keyboard. However, his fondness for alcohol during the Jazz Age damaged his health and led to his premature passing in 1931...about the time that Armstrong and Bing Crosby (who sang on several of Bix's late 1920s sessions) were merging jazz with Tin Pan Alley, extending the music's popularity.
Check Bix on the Internet and you will find a number of sites dedicated to him; Davenport honors him every year, too. For a few more days, you can hear a Bix salute on WAMU's "Hot Jazz Saturday Night," including some tracks by a Bix centennial orchestra issued in 2002. (Two feature vocals by superlative jazz singer and Lombard fan Barbara Rosene, whom we profiled a few months ago.) The broadcast will be up for a few more days. Go to http://wamu.org/programs/hjsn/.