Yes.
If the WAZA-AIR is connected via Bluetooth audio to your smartphone or tablet, you can play your guitar while listening to songs or backing tracks in your music library, or to the audio of a YouTube lesson video, etc.
Refer to "Pairing with a Mobile Device (Bluetooth Audio) " in the WAZA-AIR owner's manual.
BOSS WAZA-AIR - Explainer by Alex Hutchings "PAIRING AUDIO & STREAMING MUSIC "