“I think it’s fair to say that I’m probably not really known for my three-minute pop songs,” the English singer and multi-instrumentalist Steven Wilson said from the stage of the Best Buy Theater during his concert there on Friday night. “However, very occasionally, I can write something that clocks in at under 15 minutes that I think, you know what?, that’s not bad,” he continued as preface to “Postcard,” a four-and-a-half-minute ballad.

Mr. Wilson, who performs in Pittsburgh on Tuesday as part of a North American tour that runs through May 14, is best known as the leader of Porcupine Tree, among the foremost modern standard-bearers for the progressive-rock movement initiated in the late 1960s and early ’70s by bands like King Crimson, Yes and Genesis. Since 1987, when Mr. Wilson started Porcupine Tree as a one-man lark with a fictitious history, he has embraced the genre’s penchant for weighty themes and audiophile integrity, with well-crafted songs — whatever their duration — offsetting florid display.

Even before he put the increasingly metal-infused Porcupine Tree on hiatus in 2010, Mr. Wilson was exploring disparate styles in various enduring side projects and working with other artists as a producer and sideman. In 2008 he released the moody, arty “Insurgentes,” the first album issued under his own name.

A decisive catalyst for the direction Mr. Wilson has pursued in his solo career was an assignment to remix the King Crimson back catalog in 2009. The idiosyncratic blend of dense textures, lurching riffs and jazzy improvisation found on early King Crimson efforts like “Lizard” and “Islands” saturated Mr. Wilson’s second solo album, “Grace for Drowning,” melding with wistful pop melodies and a languid melancholy reminiscent of Pink Floyd.