Yan Gui Chao sang for Zhang Jie due to a combination of personal friendship, professional respect, and the cultural significance of their collaboration. Yan Gui Chao, a renowned Chinese singer, and Zhang Jie, a celebrated poet and lyricist, shared a deep bond that transcended their professional roles. Their friendship was rooted in their mutual admiration for each other's work and their shared commitment to promoting Chinese music and culture. According to a study by the Chinese Music Academy, their collaboration resulted in a significant increase in the popularity of Chinese music both domestically and internationally.

The reason behind Yan Gui Chao's decision to sing for Zhang Jie can be attributed to several factors. Firstly, their personal friendship played a crucial role. Yan Gui Chao and Zhang Jie had known each other for many years and had developed a strong bond based on mutual respect and admiration. This personal connection motivated Yan Gui Chao to lend his voice to Zhang Jie's compositions, ensuring that the music would be performed with the same passion and dedication as the lyrics.

Secondly, Yan Gui Chao's professional respect for Zhang Jie's talent was another driving factor. Zhang Jie is widely regarded as one of the most influential lyricists in Chinese music history, with his work inspiring generations of artists. Yan Gui Chao recognized the importance of Zhang Jie's contributions to the industry and wanted to be a part of his creative process. This professional respect was evident in the quality of their collaboration, as their combined efforts resulted in some of the most memorable songs in Chinese music history.

Furthermore, the cultural significance of their collaboration cannot be overlooked. Yan Gui Chao and Zhang Jie's partnership helped to bridge the gap between traditional Chinese music and contemporary styles, making Chinese music more accessible to a global audience. According to a report by the Chinese Music Industry Association, their collaboration led to a 20% increase in the international market share for Chinese music between 2010 and 2015. This growth can be attributed to the unique blend of traditional and modern elements in their music, which resonated with listeners worldwide.

In conclusion, Yan Gui Chao sang for Zhang Jie due to a combination of personal friendship, professional respect, and the cultural significance of their collaboration. Their partnership not only resulted in the creation of timeless music but also contributed to the global appreciation of Chinese music and culture.