From the opening mournful strains of his saxophone, Frank Glover's "Abacus" album unfolds slowly. Falling somewhere in the intersection between jazz and contemporary classical music, "Abacus" is a rewarding hybrid journey. Glover's excellent quartet --- Zach Lapidus, keyboards; Jack Helsley, bass; Dave Scalia, percussion --- is joined by a 24-piece orchestra for this three-movement work. As the title suggests, there is an almost mathematical logic to Glover's writing, but as the piece builds through "Domino" and the middle section, "Ballerina," the orchestrations take on a dream-like feeling. The interplay between the orchestra and pianist Zach Lapidus in "Ballerina" is absolutely gorgeous, building from string accompaniment to a glorious horn crescendo. Glover is a fantastic composer and arranger, not to mention his stunning work on soprano sax and clarinet. The music draws from both ethnic and modernist traditions, full of intriguing rhythm changes and mysterious voicings. Ultimately, it takes listeners on a fresh, original journey.