Adriano Orrù was born in Nuoro, Sardinia, in 1958, and has lived and worked in Cagliari for the whole of his career as a double bassist, electric bassist, composer, and music teacher. His earliest documented recording credit is a 2001 date with the Silvia Corda Trio, released on the Milan label Splasc(h). Corda, a pianist, became his most consistent musical partner over the following two decades and is also his life partner; the two are based together in Cagliari.

In 2004 Orrù and trombonist Giancarlo Schiaffini founded Impromptu, a composition-and-improvisation ensemble, and in 2005 Orrù released his first record under his own name, Solos and Duets (Ticonzero): double-bass solos alternating with duets against Schiaffini's trombone, Paolo Angeli's prepared Sardinian guitar, and Roberto Pellegrini's drums and percussion. All About Jazz's Neri Pollastri described it on release as "a work of authentic creative research," and the British magazine Double Bassist called it "a challenging but most impressive release, showing unique care for sonic effects and contrasts."

His signature solo work is Hèsperos (2011), released through the La Bèl netlabel and later reissued by the Swiss label End Titles. Its six tracks each begin from the plain sound of an open string on the double bass and build outward using a small set of ordinary objects worked against the strings and body of the instrument -- clothespins, marbles, tin cans -- rather than electronics or overdubbing. The record was included among David Nemeth's "100 Notable Netlabel Releases of 2011" for Acts of Silence, and Daniel Barbiero used it in 2015 as the central case study for an essay on "Open String Minimalism" published in Percorsi Musicali.

In 2010 he recorded Improvised Pieces For Trio (Big Round Records) with pianist Sebastiano Meloni and the English free-improvisation drummer Tony Oxley, taped live on 23 March 2008 at the Festhalle in Viersen, Germany, and reviewed by All About Jazz, Il Manifesto, and Free Jazz Blog. In 2014 his electric-bass duet record Palimpsest (Pan Y Rosas Discos) -- ten pieces built by exchanging bass lines and overdubs by file with Silvia Corda, percussionist and electronics player Mauro Sambo, and reedist Paulo Chagas -- was named Best Album in Musica Jazz's Top Jazz 2014 critics' referendum, published January 2015. In the same referendum, Geometrie Variabili, his standing quartet with guitarist Elia Casu, Corda, and percussionist Antonio Pinna, placed on the Best Group list for its record The Breath.

Since 2018 his principal working group has been Clairvoyance, a trio with soprano saxophonist Gianni Mimmo, who also runs the Amirani Records label, and Corda. Its self-titled debut was recorded on 5 November 2017 at Monserrato Studio near Cagliari and drew reviews from All About Jazz, Cadence, and California's KFJC-FM, along with a place on Perfect Sound Forever's list of 2018's best albums. A second Amirani record, Transient, followed in 2022, and a live album, Chapters of a Day, was released in 2026 on Gianni Mimmo's own Rosebud Relevant label, drawn from a February 2025 concert the trio played in Piacenza.

Orrù's other standing projects include the Palimpsest Trio with Chagas and Corda (Stanze, 2015); the duo and small-group configuration Unknown Shores, whose 2023 record The House of Memory (Fundacja Słuchaj!) was reviewed by Jazzword's Ken Waxman as "a challenging but most impressive release, showing a unique care for sonic effects and contrasts"; and a chair in the Variable Geometry Orchestra, the large international ensemble conducted by the Portuguese cellist Ernesto Rodrigues, appearing on its Creative Sources releases Quasar (2016) and Ma'adim Vallis (2018), the latter drawn from two Lisbon concerts with more than thirty performers. He also performed in the 2015 quartet MIA project Orrù Mar Rocha, alongside Portuguese violinist Maria do Mar and Brazilian clarinetist Luiz Rocha, at the MIA Festival (Meeting of Improvised Music) in Atouguia da Baleia, Portugal -- a record later named among 2015's ten best albums by the blog A Jazz Noise.

In Sardinia specifically, he has appeared in the one-off Nuoro Jazz Bass Summit, pairing four island double bassists -- Orrù, Salvatore Maltana, Sebastiano Dessanay, and Manolo Cabras -- with drummer Luca Piana, and in 2024 contributed the composition "Cosmogonia Semplice" to the anthology Compositori Sardi Contemporanei II, alongside work by twenty-seven other Sardinian composers including Silvia Corda.

His work has been reviewed continuously since the mid-2000s by All About Jazz (repeatedly, by critic Neri Pollastri), Musica Jazz, Il Manifesto, Jazzword, Cadence, Free Jazz Blog, Avant Music News, and the Italian and Portuguese improvised-music press, among others.

Orrù's playing is built outward from the double bass's most basic sound rather than toward virtuosic display: an open string, a bowed line, a single pizzicato note, examined and extended before anything else is added. Hèsperos states this method as a complete solo program, but the same instinct runs through his duo and trio work -- Il Manifesto's Mario Gamba described him in 2008 as "a master of atonal arpeggios in pizzicato, and of lines of 'dynamic stasis' with his bow." He plays both acoustic and electric bass, and treats the instrument's timbral range -- extended techniques, bowing, prepared objects -- as compositional material in its own right rather than as ornament on top of conventional lines.

Duo and trio settings, rather than a fixed working band, have been his native form for most of his career: with Schiaffini, with Corda, with Mimmo, with Chagas, and in a long list of one-off pairings assembled by file exchange (as on Palimpsest) or by festival booking (as with Oxley, or with the MIA Festival trio). Chamber-music discipline and free improvisation sit together in this work without a clear line between them, which is why his catalogue runs through improvised-music netlabels, small European free-jazz imprints, and composed-music anthologies alike.