Chris Willman Music WriterFour albums released by the Jacksons in the late 1970s and early ’80s are being reissued in expanded digital or vinyl format in February and March, as part of a campaign by the family’s original label, Epic, and Sony Music’s catalog imprint, Legacy, to re-expose the music the group made between the Jackson 5’s enormous ’60s success and Michael Jackson’s becoming the biggest star in the business with “Thriller.”Three studio albums from the ’70s are getting the expanded