The actor, who plays Broadway director Derek Wills, described Glee as "a karaoke show" and said that the two musical series are different "in every way imaginable".
"Glee's set in a high school, it's a karaoke show," he told Digital Spy. "They just do covers.
"When people sing in Glee, they sing mainly because they're teenagers whose hormones are raging so hard they have to sing it. But in our show people sing because that's the world they're in."
Davenport also defended his "abrupt and harsh" character and spoke about the "great comfort blanket" of having Steven Spielberg as executive producer.
Smash airs in the US Mondays at 10/9c on NBC. UK viewers can catch it Saturdays at 10pm on Sky Atlantic.
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