Karl's recordings as a leader can be found at CDBaby.
Karl is a featured artist on Imaginary Chicago Records.
Karl is a Velvet Strings Bass Artist.
For both classical and jazz, he plays the Garbo Set — made in Switzerland.
Karl is a Music Man Bass Artist.
He plays the Reflex Bass 5 electric bass.
Listen to Karl's Public Radio interview about Portrait of Jack Johnson.
Features a live performance of the title track by Karl's jazz trio.
Listen to Karl's Public Radio interview about Fred Anderson.
Features a live performance of "Mr. Anderson" — Karl's solo bass tribute to the legendary Chicago saxophonist.
Listen to Karl's Public Radio essay on discrimination in the jazz world.
Read "At Once Old-Timey and Avant-Garde": The Innovation and Influence of Wilbur Ware — Karl's book on the legendary Chicago bassist.
Read Karl's articles and ringside reports on boxing at East Side Boxing.
Read Karl's articles and interviews on Norse myth at The Norse Mythology Blog.