sentences:  He compiled a "tonarius", dealing with the organisation of the church chants into ‘tones’ – eight modes of the Gregorian chant.Following the reforms initiated under Abbot Immo, who imposed the Benedictine rule at Reichenau, under Berno's enlightened guidance the abbey reached its peak as a centre of learning, with a productive scriptorium, as a centre of Bendictine monasticism and eleventh-century liturgical and musical reforms in the German churches.At Reichenau he erected the tall western tower and transept that stand today on the island site of Reichenau-Mittelzell.