There's Always a Downside - S4-E4
Continuity mistake: When Myka and Jinks first see the trumpet player, the camera stays on him while he plays. At one point he plays a long tone and the camera shows him press the first two valves as if to change a note. The note he is playing continues uninterrupted however. While there are some notes that can be played with more than one fingering, changing valves in the middle of the note always produces a momentary interruption of the note, at the very least.
There's Always a Downside - S4-E4
Continuity mistake: Right at the end when Artie and Pete are talking, Artie is looking down into the bag holding the artifact. The shot changes to his other side and he is instantly looking up and into the distance.
