Tubas are available in the pitch of Eb and Bb. The Eb instrument is the favoured instrument for the wind band, orchestra and also, of course, the brass band. The Bb instrument is normally only found in the brass band, which will usually have two Ebs and two Bbs. It is available with either 3 or 4 valves, and with or without compensation. The compensation system is still the industry standard for improved tuning on large brass instruments. The system works by automatically bringing additional lengths of tubing into play when the lowest valve is used in combination with any of the other valves. This compensates for the inherent sharpness of pitch in the lower register of large piston-valved instruments.