Kala U-Bass Rumbler Fretted With BagMore Bass, less space The Kala U BASS is truly a ground breaking short scale bass that produces the same pitches as a standard bass instrument and is tuned in traditional bass tuning, E A D G. The U BASS is strung with proprietary strings that incorporate a great bass feel with balanced tension. The U BASS is a true pleasure to play, and the tone that these instruments produce is amazing. U BASSES are available in fretless and fretted, and in 4 and 5