When there stolen upon it... - Tradução em português

The sense of peace and seclusion soothed all thought and feeling in to a rapt, unearthly repose; and the balmy quiet, that deepened ever with the deepening light, seemed to hover over us with the gentler influence still, when there stolen upon it from the piano the heavenly tenderness of the music of Mozart. It was an evening of sights and sounds never to forget.

Por favor, traduzir o que está em negrito. Obrigado.