I heard more than one person at Newport marvel at the fact that Pinegrove had been booked for the smallest of the festival's three main stages. The day before its Newport set, the Montclair, N.J., band had played the main stage at the Panorama Music Festival, where headliner Frank Ocean would perform later that day. For a band that still practices in one member's parents' basement, Pinegrove has accumulated a huge, enthusiastic fan base over the year since it released its latest studio album, Cardinal.