Apart from the vocals, everything you hear is sampled.

Each piece is meticulously fixed in place in a perfect impression of a smooth, soulful swing standard.

It takes an admirable dedication to choose a method like this of recreating actual studio recordings, when you could just hire a van-load of session musicians and get the job done in half the time. And, of course, no small amount of skill to do it this way and not make it sound cold and artificial.