This dataset includes age in years (m = 35.7), music experience and sex of 13 subjects (10 males, 3 females). Columns include: primary instrument, years played of stated instrument, education style (formal/informal), and the way in which each subject memorises songs (written/ear/both). Education style and song memorisation is indicated by a "x" in the column of the given answer. Information on the frequency in which they practice, improvise and listen to music is given separately using coding where 3 = monthly, 4 = weekly, 5 = multiple times weekly, and 6 = multiple hours daily. The genre of music frequently listened to (rock, jazz, popular, other, everything) is also included in the last column of the dataset. Participants were gathered via posters and social media to recruit active musicans with improvisational experience within the Sappora area situated in Japan. Information included in the dataset was obtained from each participant using a questionnaire method. This data was gathered by a study which investigates spectral-spatial differention of brain activity using MEG during an improvisational musical performance in which mental imagery is used (Boasen, Takeshita, Kuriki & Yokosawa, 20178). **References:** Boasen, J., Takeshita,Y., Kuriki, S. & Yokosawa, K., (2018) Spectral-Spatial Differentiation of Brain Activity During Mental Imagery of Improvisational Music Performance Using MEG. *Frontiers in Human Neuroscience*, *12(156)* Retrieved from: https://doi.org/10.3389/fnhum.2018.00156.