Horacio Salgán in 2000. (Silvina Frydlewsky/For The Washington Post)

Horacio Salgán, an Argentine tango composer and pianist who helped broaden the vocabulary of his musical form and became one of the genre’s most influential and revered maestros, died Aug. 19 in Buenos Aires. He was 100.

The Argentine Society of Music Authors and Composers announced the death but provided no cause.

Like his near contemporary Astor Piazzolla, Mr. Salgán cast a mesmerizing avant-garde spell on the tango that did not always enchant musical purists in his homeland. The tango was born in the waterfront bordellos of Buenos Aires in the 1880s, and as it grew in respectability to become the nation’s signature music, it also became rigidly stylized.

Piazzolla was an outright musical revolutionary who reinvented the tango’s rhythm, harmony and form, and he was primarily an expatriate who achieved a level of international renown that overshadowed Mr. Salgán’s.

Nevertheless, Mr. Salgán remained an important musical force in Argentina, helping to forge the vanguard of the “new tango” sound in the 1950s and 1960s in a way that was less about rebellion than about synthesizing his varied, somewhat un­or­tho­dox musical influences.

Horacio Salgán and Ubaldo de Lio plays with the Quinteto Real on Saturday nights at the Club del Vino in Buenos Aires. (Silvina Frydlewsky/For The Washington Post)

Among others, Mr. Salgán drew inspiration from the U.S. jazz shadings of Tommy Dorsey and Duke Ellington, classical works by Béla Bartók and Gioachino Rossini, Brazilian choros and sambas, and African percussive rhythms. The result was deemed too uncommercial for radio airplay at the start of his bandleading career during tango’s “golden age” of the 1940s.

But the formation of his Quinteto Real (Royal Quintet) in 1960 and his five-decade collaboration as a duo with guitar virtuoso Ubaldo de Lío marked the start of a dazzling new phase in Mr. Salgán’s career.

Liberated from the need to please dancers, he crafted sophisticated instrumentals designed with listeners in mind and achieved “a brilliant balance between tradition and innovation,” music scholars Kacey Link and Kristin Wendland wrote in their recent book, “Tracing Tangueros.”

The composer toyed with countermelody and rhythm, and expressively colored his arrangements with lines for viola, cello and bass clarinet, instruments seldom found in traditional tango. But his best-known compositions — including “A Fuego Lento,” “Don Agustin Bardi” and “Grillito” — remain exquisite, even swooning, melodically. In addition to writing hundreds of his own compositions, he also arranged older tango standards to suit his protean tastes.

Mr. Salgán, who found appreciative audiences in world capitals such as New York, Tokyo and Paris, had survived the fickleness of musical tastes in his home country. By his 80s, he had outlived most of his peers and was revered in Buenos Aires as tango’s elder statesman.

“We are only now understanding just how important Salgán’s place in tango is,” Argentine-born classical conductor Daniel Barenboim told The Washington Post in 2000. “His hands do not tickle the piano, no, no. He is a man who still plays with great authority. And we don’t know how much longer we’ll have him with us, so this is the time to hang on his every note.”

Barenboim and the Venezuelan conductor Gustavo Dudamel were ardent admirers of Mr. Salgán’s music and were among those who led symphonic tributes to his tangos. The celebrated French pianist Jean-Yves Thibaudet once called Mr. Salgán “probably the only great tango pianist alive” and tried to pursue recording and touring dates with him, but the tango composer had grown too infirm.

Mr. Salgán’s music has continued to influence a new generation of tango artists and composers, among them Sonia Possetti and Juan Pablo Navarro.

Horacio Adolfo Salgán, whose father was a self-taught guitarist and pianist, was born in Buenos Aires on June 15, 1916. He began piano studies at age 6 and later distinguished himself in a local classical conservatory.

As he shifted into composing, he called upon his grounding in the classics as well as his mulatto heritage — Catalan on his father’s side, mixed race on his mother’s.

“Training in Western symphonic music opened up a whole world of harmony, orchestration and pianistic execution,” he was quoted as having said in Yale art historian Robert Farris Thompson’s book “Tango: The Art History of Love.” “But there’s also a black dimension to my music. It’s not casual, nor flagrant, but part of my origin . . . my style and my truth.”

As a young man, he accompanied silent movies on the piano, was a church organist and performed as a solo artist and accompanist on Radio Belgrano and other powerful radio stations.

His professional breakthrough came when he was 20 and a pianist with a group led by conductor Roberto Firpo. He later served as a musician and arranger for a succession of prominent tango orchestras, including one headed by the bandleader Miguel Caló.

In 1944, Mr. Salgán formed his own group in order to have greater control over how his own compositions, including the Brazilian-inspired “Choro en Fa Sostenido,” were played. But programmers deemed his three-year run on Radio Belgrano a popular flop, with pieces veering too far into dissonance and classical motifs when mass audiences wanted dance and background music. (One notable listener and admirer was Piazzolla.)

Mr. Salgán remained active as a composer, pianist and bandleader, working with the major figures of his day. But large tango orchestras were increasingly uneconomical, so he formed a duet with de Lío at the Jamaica, a Buenos Aires nightclub frequented by dignitaries of the entertainment world.

Ella Fitzgerald was reportedly so hypnotized that she recommended the duo to jazz impresario Norman Granz, who then produced their 1961 album “Buenos Aires at 3 a.m.”

Mr. Salgán’s later music partnership with pianist and composer Dante Amicarelli led to two albums, “Salgán-Amicarelli: Two Virtuosos of the Piano” (1970) and “The Magic Forest” (1971), that showed the performers at their nimble best. Mr. Salgán toured three continents in the musical show “Tango Argentina” in the early 1980s and eventually formed a new incarnation of his old Quinteto Real group, which now features his son César Salgán on piano.

He appeared in writer-director Carlos Saura’s Oscar-nominated film “Tango” (1998) and the documentary “Café de los Maestros” (2008). He also performed regularly at the Club del Vino in Buenos Aires through his early 90s. His last public performance was in 2010, but celebrations of his centennial year are ongoing, including an homage to his career at the tango festival now underway in Buenos Aires.

He was married at least four times, and a complete list of survivors could not be immediately determined.

“There are many people who come to tango or to other music genres with the idea of innovation. I came to tango neither to save it, nor for anything of the kind,” Mr. Salgán once told the Club de Tango magazine. “I, among other things, play all the genres — classical, jazz, etc. — but . . . have a respect almost religious towards music itself, because music is a bridge towards God. . . . What turned out came because I spontaneously so felt it.”