Joseph Reinhardt, nicknamed Nin-Nin, was a French guitarist of the manouche tradition and the younger brother of Django Reinhardt. He was born in Paris on March 1, 1912, in the 12th arrondissement, two years after Django, and passed away in Bondy, east of Paris, on February 24, 1982, at the age of 69. He played rhythm guitar on most of Django's prewar recordings, above all with the Quintette du Hot Club de France between 1934 and 1939, and he was one of the first guitarists in France to play an amplified instrument, performing for years on a home-made guitar of his own design. He is buried in the cemetery at Samois-sur-Seine, beside his brother.

As boys the brothers played together in cafes and dance halls. According to French Wikipedia, Joseph began on banjo in the Romani encampments, on cafe terraces and in the musette dance halls, and when Django lay in hospital after the fire in his caravan it was Joseph who brought him a guitar, since a banjo was too loud for a ward. He discovered jazz in 1931 at the home of the painter and photographer Émile Savitry in Toulon and, by 1932 and 1933, having taken up the guitar himself, he was playing with seasoned musicians, among them Coleman Hawkins.

From 1934 the Quintette du Hot Club de France took up most of his time. The first sessions of the group listed in a French session discography date from September 10 and December 28, 1934, with Joseph and Roger Chaput on rhythm guitars, Louis Vola on bass and Stéphane Grappelli on violin, and his place in the rhythm section later alternated with Pierre "Baro" Ferret and Eugène Vées. He appears on the quintet's Paris sessions through 1939, among them "Minor Swing" and "Viper's Dream" (November 25, 1937) and the March and May 1939 dates with Emmanuel Soudieux on bass. Charles Delaunay, the group's co-founder, described him as his brother's loyal, self-effacing companion, the man who carried the guitar and supplied spare strings, and the brothers' relationship was stormy enough that they sometimes came to blows.

Reinhardt stepped out on his own from 1937. On November 12, 1937 he recorded with the trumpeter Bill Coleman and Grappelli, then made a duo record with the trumpeter Philippe Brun and joined Alix Combelle's Hot Four in January 1938. In 1940 he entered the big band of Aimé Barelli and Combelle's orchestra Le Jazz de Paris, and between December 1940 and 1941 he played guitar on their sessions and on those of Hubert Rostaing, who also took the clarinet chair in the reorganized Quintette du Hot Club de France of October 1940. In 1941 and 1942 he recorded with the accordionist Gus Viseur, with the violinist Michel Warlop's trio and with the harmonica player Dany Kane, and he led an Orchestre Swing Jo Reinhardt on Decca. In December 1943 he recorded with his own ensemble, which included the violinist Claude Laurence, a pseudonym of André Hodeir; in 1944 the rhythm guitarist was Henri Crolla.

He again recorded with his brother in 1944 and 1945 and in 1947 and 1948, among them the March 26, 1947 Quintette session with Grappelli and Jean "Matelot" Ferret on rhythm guitar, the Rostaing quintet dates of July and October 1947, and the November 1947 sessions with Grappelli, Vées and the bassist Fred Ermelin. On October 17, 1947 he was the guitarist, with Chaput on rhythm guitar, on a session billed to Grappelli's Hot Four. After Django's death in 1953 he stopped playing for a time and, French Wikipedia reports, kept an empty chair on stage in his brother's memory. He appeared in Paul Paviot's 1957 documentary film on Django, played an electric guitar of his own construction in the 1950s and 1960s, and led a string quintet with the violinists Pierre Ramonet and Vivian Villerstein in the clubs of the Latin Quarter. Ramonet plays on his 10-inch LP Joseph Reinhardt joue... Django (Les Discophiles Français, 1958), and in October 1959 Decca issued his EP Mon pote le gitan with the singer Jacques Vérieres. His later albums include Hommage à Django Reinhardt and Live in Paris 1966, the latter recorded with the guitarists Jacques Montagne and Henri "Dingo" Adel and the bassist Benoît Charvet and issued on CD by Hot Club Records in 1991. In 1978 he was photographed at the Django Reinhardt Festival in Samois-sur-Seine, where his nephew Lousson, Django's son, also played.

French Wikipedia describes Joseph as a more abrupt and less sophisticated stylist than his brother, and also as a gifted arranger. His role for most of the 1930s was rhythmic: on the Quintette records he is the steady chordal support behind Django's solos, which is why his name appears so often beside Roger Chaput's, Baro Ferret's and Eugène Vées's in the personnel lists. Out from under that role, his own records of the late 1950s and 1960s are mostly his brother's repertoire, "Nuages", "Djangology", "Manoir de mes rêves" and "Minor Swing", alongside pieces of his own such as "Violons", "Bric à Brac", "Triste mélodie" and "Menuet" credited to him on Hommage à Django Reinhardt. French Wikipedia adds that he followed younger guitarists with interest, naming Jimmy Raney and Wes Montgomery, and that Montgomery once answered him in concert with a string bend, a gesture he did not otherwise use but which was a signature of Django. Shortly before his death he told the young Biréli Lagrène that he had the same right hand as his brother. French Wikipedia counts him, with the Ferret brothers (among them Matelo Ferret) and the guitarist Francis-Alfred Moerman, among the players who carried manouche jazz forward, helped by his frequent appearances at the cafe La Chope des Puces in Saint-Ouen. AllMusic classes his work as jazz, with the styles guitar jazz and swing, which is why the Gypsy Jazz and Swing tags are used here.