These characters combine logically: 吉他 (jítā) is a phonetic loanword for “guitar,” and adding 手 (shǒu) turns it into “guitar-person,” or “guitarist.”
The term 吉他手 (jítāshǒu) itself doesn't have deep ancient roots, but the figure of the guitarist holds significant cultural weight in modern China. The guitar, and by extension the guitarist, became a powerful symbol of youth culture, individuality, and Western influence during China's “opening up” period in the 1980s. Artists like Cui Jian (崔健), often called the “Father of Chinese Rock,” used the electric guitar to voice the feelings of a new generation. The image of a lone guitarist became iconic, representing a departure from more traditional, collectivist art forms. This can be contrasted with a musician playing a traditional Chinese instrument like the guzheng (古筝) or erhu (二胡). While both are respected musicians, the 吉他手 often evokes a more modern, independent, and sometimes rebellious spirit, tied to global pop and rock culture. The guitarist is the quintessential member of a 乐队 (yuèduì), or “band,” a concept that emphasizes collaborative creation and performance in a very contemporary way.
吉他手 is used in exactly the same way “guitarist” is in English. It's a neutral term appropriate for any situation, from casual conversation to formal media.
The term is universally understood by all age groups familiar with modern music.