The definition of a musician in music psychology: A literature review and the six-year rule

The aim of this paper was to investigate if a general consensus could be established for the term "musician." Research papers (N = 730) published between 2011 and 2017 were searched. Of these, 95 papers were identified as investigating relationships of any sort connected with a musician-like category (e.g., comparison of musically trained vs. non-musically trained people), of which 39 papers detailing comparative studies exclusively between musicians and non-musicians were analyzed. Within this literature, a variety of musical expertise criteria were used to define musicians, with years of music training (51% of papers) and years of music lessons (13% of papers) being the most commonly used criteria. Findings confirm a general consensus in the literature, namely, that a musician, whether or not selected a priori, has at least six years of musical expertise (IQR = 4.0-10.0 years). Other factors such as practice time and recruiting location of musicians were also analyzed, as well as the implications of how this definition fits in relation to the complexities surrounding the construct of the musician. The "six-year rule," however, was robust overall.