From the Broadway in Boston website:
Set in a beach resort in the Mediterranean, Mamma Mia! tells the story of Sophie, a bride-to-be with one wish: to have her absent father walk her down the aisle. After reading passages about three old lovers in her mom’s diary, Sophie sends each a wedding invitation in hopes of learning which is her dad. The arrival of the men from her past is surprising to Donna, Sophie’s fiercely independent mother, who prides herself on getting through life without a man, and highly amusing to Donna’s two best gal pals. The more Sophie and her mother struggle to find truth and understanding, the more it threatens to tear them apart and wreck Sophie’s dream wedding.