This was too cool of a find not to do. Its a public domain source from Wikimedia Commons showing the evolution of musical instruments from conch shell to trumpet! AMAZING! I uploaded three versions because I couldn't decide which is better. Feedback on them? Source: http://commons.wikimedia.org/wiki/File:History_of_Inventions_USNM_42_Wind_Muscial_Instruments.jpg al
樂器灰度的歷史
conch、creation、evolution、filter grayscale、instruments、music、musical、shell、sound、trombone、trumpet、upload2openclipart
海螺、創建、演化、過濾灰度、儀器、音樂、音樂、貝殼、聲音、長號、喇叭、upload2openclipart
資料來源：openclipart ( https://openclipart.org/ )