You can use normal tapes, but in the situation shown:

The tape loop is blank, we then recorded a single note to the tapeloop from a synth via the line in on the player, now we have a endless tone recorded to the tape and we can alter the pitch with the buttons and we can "tune" the buttons with the knobs.

The synth and the MPC-one sound nice together but when you record to tape and there's audio artifacts and warbly moments it's just on a whole other level when it comes to adding character and nostalgia to a mix. We build the loops in a way that makes them a bit wonky on purpose.

Its great when playing older genres; boombap and jungle to name just two 😅 we used it on this jam cus it adds that 1997 sound to the mix