If you're a fan of Michael Fassbender, Ryan Gosling, Natalie Portman, Rooney Mara—all of whom star in Song to Song—then by all means, give it a spin. I'm a fan of each of these great actors, however I questioned their judgement and motivation in taking these roles. Cook (Fassbender) is a music biz bigwig, Rhonda (Portman) is a diner waitress who used to be a kindergarten teacher, and Faye (Mara) and BV (Gosling) are songwriters. There's absolutely no reason in the world why a skilled, experienced filmmaker couldn't craft some sort of interesting study around these characters, even while eschewing traditional narrative. Especially with these actors. But Malick wastes two hours tracing their romantic lives in such a detached fashion, one wonders why he expected anyone to care.
Small roles by the likes of Cate Blanchett, Holly Hunter, and Val Kilmer—plus a bunch of cameos by musicians including Patti Smith, Flea, Florence Welch (of Florence and the Machine), and numerous others—might catch the eye of many a looky-loo. But Malick so strenuously maintains an overall air of inconsequentiality, all the famous faces in the world can't enliven this DOA film. As its main characters bounce around from concert to concert, waxing pseudo-philosophical about love and life, Michael Winterbottom's similar stab at rock-scored nothingness, 9 Songs (2004), came to mind. At least that one interjected hardcore sex scenes at regular intervals to keep things interesting. Luca Guadagnino's 2015 A Bigger Splash also shares some stylistic similarities (and, at least superficially, some similar themes), but its intriguing thriller elements are infinitely more recommendable than the flat-liner that is Song to Song.
Malick's waste of time and resources could be (and has been) called "experimental." But using a GoPro camera to capture odd, often unflattering angles while your Oscar-caliber cast drifts by—seemingly unsure what they're supposed to be doing at any given moment—doesn't constitute experimentation. That would take some forethought and energy. This is just lazy.