Nostalgia is usually an enjoyable look back at the highlights of yesteryear, now digitally championed in BuzzFeed lists and Twitter hashtags, but the theme is given a darker twist in the debut single from UK singer-songwriter Martin Luke Brown. “Would the kid you used to be still be proud of you?” he asks before continuing to question old memories and whether those memories act as a catalyst for action or become haunting, restrictive shackles. He sings a wistful reminder that nostalgia isn’t always a positive action — that looking back can sometimes get you stuck in the past, rather than moving forward; and that the dreams and passions built as a child may have been eroded by the struggles of the adult world. For Brown, though, “Nostalgia” is a powerful pop single, whose reflective, relatable lyrics are accompanied by keyboards and light percussion that recall the styles of OneRepublic and Mikky Ekko, making it a likely positive catalyst for a formidable music career.