This study aimed to create the double bass workbook that focuses on critical thinking and the efficiency of learning. studied. The research tools were: 1) The double bass workbook for children (7-9 years old). and 2) an assessment and interview form. https://www.nacrack.com/mega-choice-2005-2006-NISSAN-ALTIMA-Radio-Receiver-AM-FM-stereo-single-CD-Player-G-mega-value/