You draw the keyswitch notes in the piano roll to play the section you need, it will also play GM midi.
It is actual recordings of Real Drummers, you can adjust the individual levels and create you own fills, solos or riffs.


https://www.youtube.com/watch?v=Jrnf59wPBuk


https://www.youtube.com/watch?v=0aShNYdq6n0


https://www.youtube.com/watch?v=ErGiiZX-Vms

Virtual Drummer PHAT combines the living and breathing performance of a
session drummer with the sonic versatility and competence of a professional
engineer in a world-class studio – all in one easy-to-use plugin.
Virtual Drummer PHAT features a selection of professionally recorded drum kits
and groove styles, integrated with professional mixing gear, all waiting to be
fired off and arranged using your MIDI controller in real-time. With Virtual
Drummer PHAT you’ll be producing professional drum tracks in no time.
Virtual Drummer PHAT has been developed for everyone who finds drum loops
too limiting and programming MIDI drum arrangements too tedious or
challenging. Laying down a drum track is now super easy: Select a Drum kit and
a Style, control the drum performance in real-time by selecting song parts from
a MIDI keyboard – Virtual Drummer PHAT will play along, always perfectly in
sync with your performance.
As in the real world – the drum kit is professionally miked up and mixed, with the
most powerful options available for you to get exactly the sound you want.