Treble clef, alto clef and soprano clefs are all used by different composers. The clefs used are based on alto clef (imagining that you are playing a viola). Mensural notation generally uses C and F clefs, on various lines. Other heavy stands are made of brass, and feature musical motifs such as treble clefs. It is possible to switch between treble and bass clefs. Octave clefs may be used to indicate the sounding pitch, but usage is inconsistent. Of these, the treble and bass clefs are by far the most common. He made use of clefs (C & F clefs) and invented the "ut-re-mi-fa-sol-la" notation. Some instruments regularly use both clefs, such as piano and pipe organ. At the time, composers like Boccherini sometimes wrote cello parts in five different clefs. Their music symbols mainly consist of clefs. This entails particular challenges of tuning and time, sometimes resulting in unusual clefs. Lewis would eventually join a jazz group called the clefs. Varying shapes of different clefs persisted until very recent times. There are no different clefs for the left and right hand.