He has been praised by former Wisconsin coach Barry Alvarez as being one of the primary reasons why the Badgers were able to turn their program around and eventually win three Rose Bowls in the 1990s.
Alvarez cited Callahan specifically for his strong recruiting abilities.
In person, his cowboy baritone often decrescendos to a whisper.
Still, his eyes flicker with passion when he talks about things like the difference between songwriting and prose, or how genetically modified meat wrecks our bodies. All my last albums have had really long titles and I wanted something short and snappy. And you know, it applies to some of the subject of the songs.
Callahan recently released his 13th studio album, . More the revelation type of apocalypse than the end of the world.