I am guessing (as this is a “getting started – argghhhh” video) that he did this for edutainment purposes. People do mashup live and use all these FX and samples, but the time between them would normally be (a lot) longer. You’d let more of the tracks play in between. Imho the audience will “hook” onto a good track, with a aha-moment as they recognise the track. As they settle in to dance/listen to the familiar track, it’s already gone in this case. My experience is that the audience really doesn’t dig that too much. As a part of a set, say a minute mashup or so, it’s nice. But not like this guy does.
I am guessing this was Ableton or something alike on the MacBook with the APC controlling the samples/tracks. The FX all straight from the DJM900 box. Those FX are beatsynced either automatically or via tap, so no big surprises there as you stated.
As for my opinion on this guy, he should actually open his mouth when talking, rather than speak with semi-clenched teeth. And slow his speech a little. It would improve his presentation and his clarity of speech by quite a bit. Again, just my opinion.
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