I love "In Da Club". It is very simple in terms of arrangement, but this is actually its strength.
The medium-speed backing track could not be more sparse. It hardly changes for the whole of the song. Quite quiet orchestral string-crashes do an offbeat "......duh.DUH...duh.DUH...duh.DUH". This is exactly the rhythm also followed by the bass drum in the rhythm, and followed by the bass line as well!
So how can such a simple rhythm work? Well it's all thanks to the rap. The rapping over the top is done is a very cool, deep and calm voice. Its rhythmic effect is great. The rapper's skill provides all the variety of rhythm and timbre that is needed to complete the song.
The rapping is done in an almost "throw-away" tone of voice, though is anything but throw away. The chorus is rapped in the same way as the verse, but you can tell it is the chorus by subtle changes (he raps it all on a single tone, almost a one-note melody). The subtlety of these changes adds to the coolness and flow of the song. Tension is raised before chorus by simply adding higher notes to the orchestral string hits, and by adding an underlying repeated single note rhythmic flow.
The feel of this track is more "dark and bassy" than a lot of chart rap. This has much to do with the sound of the rappers voice, and the simple arrangement. I could imagine this playing on a dark bouncing club dance floor and moving the whole crowd brilliantly.
An excellent single from 50 cent. Simple, effective, skillful, cool and will be a great mover for when you're "in da club".