This is the Settings icon in Musictheory.net, located in the top right section of the Menu Bar. Under Settings, choose "Clefs" to change the Note Identification exercise between Treble Clef and Bass Clef.
Treble Clef Band Instruments
Flute
Clarinet
Alto Saxophone
Trumpet
Also - Recorders and Ukuleles are written in Treble Clef
Bass Clef Band Instruments
Trombone
Electric Bass
This is an easy-to-use online drum machine where you can set up rhythms on an electronic drum kit and play your patterns. Lots of fun! See what kinds of rhythms you can play - try different time signatures and patterns. Note: each section you can select is equivalent to a 16th note (half of an 8th note).