Of Dutch Jewish heritage and the son of a diamond setter, Hambro was born in the Bronx in October 1923 and lived in, or in the vicinity of New York City for the majority of his life.

[1] Lenny lived with his parents and older sister, Adelaide, in an apartment at 984 Sheridan Avenue – just a few blocks northeast of old Yankee Stadium, which was completed the year of his birth.

[3] After his father's death from pneumonia when Lenny was 28, Hambro largely lived "out of a suitcase", but, when in New York, stayed with older sister, Adelaide, and her husband, Harold, in the Bronx, until his marriage in 1960.

[2] As a high school student, Hambro took private lessons from Bill Sheiner, one of the leading music teachers and session musicians in New York City.

[2] (Years later, Hambro would return to the Catskills, playing with Machito's Orchestra at the Concord Resort Hotel, and during another summer, had his own quintet in the lounge.

[7] Although initially skeptical, Krupa and trumpeter Roy Eldridge were impressed and called Hambro at home the next day to tell him that he had secured the job and to schedule him for a tuxedo fitting.

(Hambro, along with tenor saxophonist Buddy Wise and trombonist Frank Rosolino, is featured in a 15-minute film short, Deep Purple, directed by Will Cowan in 1949, which focused on Gene Krupa and His Orchestra.

He continued to hone his own skills by studying clarinet with Leon Russianoff and flute with Henry Zlotnick, both of the Manhattan School of Music.

Over the next two years, the members of the quintet alternately included Wade Legge, Rene Hernandez, Eddie Costa, or Hank Jones on piano; Dick Garcia, Sal Salvador, or Barry Galbraith on guitar; Louis Barretto, Clyde Lombardi or Arnold Fishkind on bass; Eddie Bert on trombone; Mel Zelnick, Harold Granowsky, Gus Johnson Jr., or Sid Bulkin on drums; Jose Mangual, Ubaldo Nieto, and Ray "Mongo" Santamaria on Bongos/Congas; and Babs Gonzales' vocals.

The band toured the United States routinely during this period as well as England, Poland, "Iron Curtain" Europe, and North Africa in 1957 and 1958, where they played at U.S. military facilities and Embassies; and Japan twice in the early 1960s.

[12] Lenny was with the New Glenn Miller Orchestra for eight years, during which time they played a live 13-week summer replacement show on CBS, co-hosted by McKinley and vocalist Johnny Desmond ("Glenn Miller Time", 1961; broadcast from the Ed Sullivan Theater in NYC; see External links), and the NBC Bandstand on both radio and television, and cut seven albums for RCA Victor.

At age 10, she took first place during an appearance on Paul Whiteman's Philadelphia-based Saturday morning talent show, TV Teen Club (an indirect predecessor to American Bandstand).

When Michels graduated from high school, she went to work for the Matys Brothers, a rockabilly and later polka band from the Philadelphia area that was part of Bill Haley's stable.

Hambro continued working the clubs of New York City, Philadelphia, and Miami, and played the famed Rainbow Grill in midtown Manhattan during 1968–69 with a small combo led by old friend, Ray McKinley.

[33] In 1970, Hambro led and managed the orchestra for vocalist Warren Covington and did two half-hour specials on CBS television in the fall, before returning to work as a booking agent in 1971.

[34] He was also a regular – along with Paquito D'Rivera, his wife Brenda, Daniel Ponce, Victor Paz, Candido Camero, Tom Malone, Marvin Stamm, Jorge Dalto, Jon Faddis and Ruben Blades – at morning sessions in New York City, recording jingles for radio and TV commercials, led by his friend and former bandleader, Chico O'Farrill.

[38] Hambro also continued to do club work, putting together a quartet under his name, notably accompanying Anita O'Day at Michel's Pub from September 1975 to January 1976.

Beginning in September 1981, Hambro booked the big bands of Duke Ellington, Tommy Dorsey, Glenn Miller, Count Basie and The Royal Canadians.

[12] During this time, he remained active as a working musician, playing Philadelphia jazz clubs with myriad groups, and taking various gigs, including touring Europe with pianist Peter Duchin.

He taught private lessons, played in a variety of bands, both big and small, in Miami-Fort Lauderdale area jazz clubs, and continued to work as a booking agent.

He also continued to readily donate his talents to charity fund raisers, most notably working with Jack Simpson to benefit the Brevard County Food Bank.

However, suffering from severe chest pains, and told that he would need bypass surgery and a heart valve replacement, Hambro returned to New Jersey in early 1995 to be close to his sons, his wife, and the doctors with whom he was comfortable; and to work on Chico O'Farrill's comeback album.

On the day of his marriage, Hambro and the 17-member The New Glenn Miller Orchestra were playing one of the ballrooms of Philadelphia's Bellevue-Stratford Hotel, while his fiancée, Lynn Michels, was singing with Al Raymond's big band in another room.

On Monday, with Hambro and Michels following the tour bus in their new convertible, the band headed to the Midwest for two weeks of engagements, followed by dates in Louisiana and Texas.

After a brief respite for Hanukkah/Christmas, they broadcast from the Aragon Ballroom in Chicago on New Year's Eve, and after the post-Christmas break, a few weeks later, on January 19, 1961, they performed at one of President John F. Kennedy's five inaugural balls in Washington, DC.

[49] The band's repertoire in January 1957 (during an extended engagement at the Cafe Rouge at the New York Statler Hotel, including Sunday afternoon's Treasury Savings Shows) included 60 Glenn Miller originals, 10 McKinley standards, 10 contemporary tunes done in the Glenn Miller style (thanks to arranger Joe Cribari) and several pieces by the Lenny Hambro Quintet.

[55] As a composer, Hambro is best known for "The Lonely One", written with Roberta Heller (then a 21-year-old lyricist for music publisher Ivan Mogull,[56]) which Nat King Cole recorded for Capitol in 1956.

It has been covered over the years by a variety of artists, including Gene Tierney, Marianne Solivan, Sil Austin, Kitty Kallen, Kelly Friesen, Lisa Ekdahl, Mark Doyle, the Robin Nolan Trio, the Music Rama Band, and by several Finnish bands, where it was a minor hit as "Tuo Onneton" (with Finnish Lyrics by Kari Tuomisaari).

[38] He played his alto with a light, sweeping style that moved along gracefully and, on ballads, had a sweet, singing tone that was, in essence, a trimmed-down version of Johnny Hodges' technique.

[59] After 1967, Hambro experimented with the Selmer Varitone electronic pickup and effects unit, which can be heard on Chico O'Farrill's 1968 album, "Married Well", and 1995's "More Than Mambo: Introduction To Afro-Cuban Jazz", both from Verve.