澳門出世，讀過粵華中學，1974年畢業後參加過香港無線電視旨在挖掘歌唱人才嘅節目《聲寶之夜》，靠翻唱《Congratulations》一曲入到決賽，跟住去香港發展，加入娛樂圈。1976年，被無線金牌編導甘國亮賞識，演出第一套劇集《少年十五二十時》。嗰一年，賈思樂同森森、斑斑、李振輝合作拍攝《四樂士特輯》歌唱節目，之後同EMI簽約。
Born in Macau, he studied at Yuehua Middle School, and after graduating in 1974, he participated in the Hong Kong TVB program "Shengbao Night", which aimed to tap singing talents, and reached the finals by covering the song "Congratulations", and then went to Hong Kong to develop and join the entertainment industry. In 1976, he was appreciated by the wireless gold medal choreographer So Guoliang and performed the first set of dramas "Youth Fifteen and Twenty Hours". That year, Jia Sile cooperated with Sen Sen, Banban, and Li Zhenhui to shoot the singing program "Four Musicians Special", and then signed a contract with EMI.