On iOS, Triode has a Presentation Mode that provides a minimal user interface where you just see album artwork and the name of what's playing.
 

To enter this mode, tap on the text of the currently playing track. The controls will slide off screen and the background will match the artwork.
 

In this mode, you can quickly mute the sound by tapping on the artwork. To get out of presentation mode, just tap on the text again.
 

If you're using Triode while you work and your iPhone is connected to a charger, check out the setting to Keep Display On.