The title of Ghost Bridge, the East-Coast-spanning chamber ensemble Hour's fifth record, is less metaphorical than one might expect. Bandleader Michael Cormier-O'Leary repurposed it from an unrealized movie concept about a bridge that inexplicably starts disappearing. On the nearly-ten-minute title track of this richly imaginative suite of songs-written for a 13-piece ensemble that includes woodwinds, strings, and vibraphone as well as a rock rhythm section-Hour conjures up this central image with spectral string harmonics and free-time percussion gestures. While writing the keyboard pieces that became the takeoff point for the album, Cormier-O'Leary also found himself reflecting on the loss of loved ones or even his own mortality. The six kaleidoscopic instrumental pieces on Ghost Bridge, though, feel more cosmically inquisitive than straightforwardly elegiac, sketching a progression from existential doubt toward understanding and acceptance.Ghost Bridge forms a contrast with Hour's art-rock-informed, more improvisatory early releases, representing a step further into intricate chamber orchestration. Known for his work with Friendship, Wendy Eisenberg, and 2nd Grade, Philly-based multi-instrumentalist and Dear Life Records founder Cormier-O'Leary has made Hour a home for increasingly cinematic instrumental compositions since the mid-2010s. With dazzling production by Lucas Knapp, Ghost Bridge delivers plenty of the live ensemble's trademarks, especially cyclically developing guitar and keyboard melodies. However, even more than on Hour's last studio album, unconventional harmonies and sophisticated counterpoint take center stage here. These emotionally multifaceted compositions feel as rooted in contemporary classical and film soundtrack music as in indie rock.One of the most striking elements of Ghost Bridge is the more significant developmental role the orchestral instruments assume in each piece. Instead of underscoring Cormier-O'Leary's central hooks, there is a new mesmerizing level of detail to the group's conversational interactions and kinetic energy. ""Centralia"" is a stately and idiosyncratic fugue built from repeated and overlapping phrases, while Ghost Bridge's compositions are full of unexpected pivots in harmony that allow recurring melodic motifs to sound continually reshaded. On ""Pearls,"" the chords modulate drastically around Cormier-O'Leary's inviting central melody in a way that emulates cuts in a film telling several parallel stories.There is an unsettled quality to the chords on Ghost Bridge, with Cormier-O'Leary's progressions avoiding firm grounding in either clearly sunny or melancholy tonalities. This mood is made more concrete by the record's sole vocal track, the jazz-inflected ""Sky is Blue,"" featuring an uncannily gorgeous performance by Heeyoon Won. The song seems to be a communication from a person who has departed, offering consolation or perspective to someone left behind. Though it's sonic palette is often tranquil, Ghost Bridge explores heartbreak, grief, anger, and helplessness in a distinct and pretense-free way. The project represents a bold step forward for Cormier-O'Leary as a composer and arranger, and on Ghost Bridge Hour reaches it's most fully realized form to date, connecting soaring themes with an inventiveness that perfectly suits the searching nature of the subject matter.