I am looking for any materials that could help me with my research on what motivates people to attend music festivals. It could be past research, journals, books, anything will be helpful really.
Not at this moment, but I do not understand clearly your interest. Music festivals (traditional music?) because it all depends of the musicians, if they are famous or populars, the money and the media.
It would be helpful for you to clarify the term music festivals. Do you mean the festivals where school bands and choirs perform competitively and for feedback? Do you mean public events such as jazz festivals where amateur and professional performers appear, or community music festivals such as the annual events that may draw tourists, such as SummerFest in Milwaukee, WI? Once we understand the scope of your research more clearly, it will be possible to advise potential sources.