Charles Samuel Loeb was born on December 7, 1955, in Nyack, New York, a Hudson River town north of New York City. He began playing guitar at 11 and was gigging in local bands by 13. The first song he learned was Bob Dylan's "Like a Rolling Stone," and he grew up on Jimi Hendrix, Eric Clapton, Cream, Led Zeppelin and the Beatles. At 16 he found jazz through the records of Wes Montgomery, George Benson, John McLaughlin and Pat Martino, and decided that music was all he wanted to do. He studied with the Philadelphia guitar teacher Dennis Sandole, who sent him on to Jim Hall in New York, and he spent two years at Berklee College of Music in Boston before leaving in 1976 to look for professional work in New York.

In New York he worked as a sideman with Chico Hamilton, Ray Barretto, Hubert Laws and Freddie Hubbard. Around 1979 Stan Getz hired him, and he stayed in the saxophonist's band for roughly five years, eventually serving as its musical director, according to JazzTimes. The group in those years also held keyboardist Mitchel Forman, bassist Mark Egan and drummer Victor Lewis. Loeb wrote five of the eight pieces on Billy Highstreet Samba, a Getz album recorded in Paris in 1981 and released on EmArcy in 1990. Touring with Getz also led to his marriage: he met the Spanish singer Carmen Cuesta on the road, and Getz was best man at their wedding. They raised two daughters, Lizzy and Christina, who later sang on his records.

In 1984, by JazzTimes's count, Loeb joined Michael Brecker in Steps Ahead, the group led by vibraphonist Mike Mainieri, and toured and recorded with it for several years. On Magnetic (Elektra/Musician, 1986) he is credited on acoustic guitar, electric guitar and guitar synthesizer, and he co-wrote the piece "Beirut" with Brecker, Mainieri, drummer Peter Erskine and bassist Victor Bailey. Alongside the touring he did a great deal of New York studio work: jingles, television themes and film dates. His credits include theme music for ABC's Nightline, the daytime serial One Life to Live, the Montel Williams Show, the New York Yankees and Knicks and ESPN's college basketball, along with the CNN Headline News theme that bassist Will Lee called one of the most-heard pieces of music in the world. He played on the scores for The Untouchables, You've Got Mail and Hitch.

His own records began with My Shining Hour (1988), made for the Japanese label Pony Canyon, and a run on DMP (Digital Music Products) that included Life Colors (1990), Balance (1991), Mediterranean (1992) and Simple Things (1994). He also became a producer for other players, among them Donald Harrison, Nelson Rangell, Larry Coryell, George Garzone and Warren Bernhardt. With Forman he formed Metro, a fusion band whose first album appeared in 1994, and he recorded three albums with the Fantasy Band, with Dave Samuels and George Jinda. The commercial breakthrough came on Shanachie with The Music Inside (1996), whose title track spent six weeks at number one on the jazz charts. Six more Shanachie albums followed through When I'm With You (2005), including Listen (1999), In a Heartbeat (2001), All There Is (2002) and eBop (2003).

In 2007 he moved to Heads Up International for Presence and then Between 2 Worlds (2009), a pared-down guitar, bass and drums date. Plain 'n' Simple (2011) revisited the 1960s organ-trio tradition, and Silhouette (2013) set him in front of four different ensembles, among them a group with drummer Peter Erskine and an organ trio with Pat Bianchi, with his daughters singing on some tracks. In 2015 he made Bridges with saxophonist Eric Marienthal, and the same year Metro recorded Big Band Boom with the WDR Big Band Cologne under Michael Abene. His last album, Unspoken (2016), brought in Jeff Lorber, Nathan East, Andy Snitzer and Till Brönner.

In February 2010 Larry Carlton left Fourplay, and Loeb took the guitar chair beside Bob James, Nathan East and Harvey Mason. Let's Touch the Sky (2010) was his first record with the quartet, followed by Esprit de Four (2012) and Silver (2015). His composition "December Dream," from Esprit de Four, was nominated for the Grammy for Best Instrumental Composition at the 2013 ceremony. He was nominated again for Jazz Funk Soul (2014), a trio record with keyboardist Jeff Lorber and saxophonist Everette Harp, at the 2015 ceremony, and for Unspoken at the 2017 ceremony, both in the Best Contemporary Instrumental Album category. Grammy.com lists three nominations and no wins.

Loeb had been living with cancer for several years when he passed away on July 31, 2017, at the age of 61. He is survived by Carmen Cuesta and their daughters. He had lived most of his life in the Nyack area, and JazzTimes's obituary described him as unassuming and devoted to his family.

Loeb played in more than one world and said so with his repertoire. His grounding was the lineage of Wes Montgomery, George Benson and Pat Martino, filtered through the rock records he started on, and his work on record ran from bebop-based organ-trio playing to polished instrumental pop. Dave Love, who ran Heads Up when Loeb recorded for it, described his music as moving easily between straight-ahead jazz, contemporary jazz and Brazilian music, and his wife's Spanish-language records, which he produced, fed a Latin side as well. He named Michael Brecker as an important influence from his Steps Ahead years. The smooth jazz side is a large part of his story and is stated plainly here: Wikipedia and AllMusic both list smooth jazz among his styles, his title track "The Music Inside" topped the jazz charts for six weeks, and Fourplay is one of the format's best-known groups. Alongside it ran the working-jazz musician's habits. He proposed a Wes Montgomery tribute concert for the Berks Jazz Fest in Reading, Pennsylvania, that put seven guitarists on one stage: Loeb, Larry Carlton, Russell Malone, Pat Martino, Paul Jackson Jr., Earl Klugh and Jimmy Bruno. As a composer, producer and arranger he was as busy outside his own albums as on them, and bassist Will Lee said Loeb heard the music in everyone he played with and knew how to draw it out.