Having kept himself busy with a national summer tour, the enduring Nikos Portokaloglou, a top seller on the domestic pop-rock scene, has left his itinerary’s biggest show for last, at the open-air Lycabettus Theater tonight. The show, in support of the Spastics Society, will include guest appearances from several artists who have collaborated with Portokaloglou over the years. They include Alkinoos Ioannidis, Yiannis Kotsiras, Andriana Babali and Eleni Tsaligopoulou, as well as Cretan musician Manos Pyrovolakis, whose infectious blend of homeland folk and rock have made him one of the local circuit’s brighter pop stars. The set list will be career-spanning with renditions by Portokaloglou and his guests of old and new material, ranging from songs by Fatme, the popular rock group Portokaloglou fronted throughout the 1990s before embarking on a commercially successful solo career, to fresh material from a forthcoming album due for release next month. Portokaloglou, who bases the majority of his songwriting in the rock style, surprised fans a couple of years ago by entering the grounds of old popular Greek (laika) standards as part of a series of shows with veteran act Dionysis Savvopoulos and the gritty laika singer Giorgos Margaritis. Nikos Portokaloglou and friends will be backed by the frontman’s regular touring band, which is made up of Stathis Drogosis, Vassiliki Karacosta and Odysseas Tsakalos.