The bassline in Heartbeat is peak 2009 electro. It’s got that gritty, distorted Klaas sound that you just don't hear much anymore in modern house.
While Klaas is perhaps most famous for his remix of "Infinity 2008," "Heartbeat" solidified his status as a solo producer who could command a dance floor without relying on a legacy sample. It captures a specific moment in electronic music history where the genre shifted from the smooth loops of 90s house into the aggressive, "maximalist" sound of the digital age. Listener Perspective Klaas - Heartbeat (Official Video HD)
I remember this playing in every club. It wasn't about the lyrics; it was about that massive pumping side-chain that made the whole room move. The bassline in Heartbeat is peak 2009 electro