Instagram/John Summit & Subtronics Music John Summit's Experts Only 2026 lineup is here! See Summit solo, Subjohnics with Subtronics, plus Prospa, LYNY, Partiboi69, Gabss & more. April 1, 2026 AceShowbiz - The phase one lineup for the 2026 edition of John Summit's Experts Only festival has been officially announced, building excitement for the event's return. At the forefront is John Summit himself, who is set to perform not only a solo set but also collaborate with Subtronics in their joint project, Subjohnics.