There's a lot more to Propellerhead Reason 4 than just a brand, new arpeggiator, and in this screencast, Bill Holland opens up Thor and battles the God of thunder sized synthesizer. Bill overviews some of the features here including multiple oscillators and the parameters you can control in Thor.

Stay tuned for more on the Thor polyphonic synth in Reason 4 as we take a closer, more detail-oriented look at some of the individual features.