We say in the prayer (blessings of the Shema): "Moses and the children of Israel sang a song to You with great joy, and they all said, etc., together they all gave thanks and proclaimed Your kingship and said." This needs explanation, as it already states that Moses and the children of Israel sang the song, so the continuation, 'all' and 'together,' seems to be redundant. It implies a special emphasis, that they sang the song together, and this needs further explanation.