[1] As a classical contemporary composer he is noted as a representative of a reorientation toward tradition, tonality and melody, and his works have been lauded by critics[2][3][4] in Norway and abroad.

Marcus Paus has set to music poets and writers such as Dorothy Parker, W. B. Yeats, Oscar Wilde, Siegfried Sassoon, Richard Wilbur, William Shakespeare, Christina Rossetti, Emily Dickinson and Anne Frank, and Norwegians André Bjerke, Jens Bjørneboe, Arne Garborg, Knut Hamsun, Johan Falkberget, Harald Sverdrup and Ole Paus.

Ella's father, the Viennese lawyer August Stein (1852–1890),[12] left the Jewish Community of Vienna in 1877,[13] had his children baptized as Catholics in 1885 and converted to Catholicism himself the following year.

The Paus family belonged to the regional elite governing Upper Telemark from the early 17th century, the "aristocracy of officials" consisting of judges and priests of the state Church of Norway.

In 2019 he married the composer and singer Tirill Mohn, a former member of the art rock band White Willow and a descendant of the artists Christian Krohg and Oda Krohg; he and his wife are distantly related as both are descendants of Norway's first attorney-general Bredo Henrik von Munthe af Morgenstierne Sr.[14] Paus attended Oslo Waldorf School.

Paus's breakthrough as a leading young composer came in 2008, with Missa Concertante, written for the Oslo International Church Music Festival.

Although often tonal and melodically driven, Paus's music employs a wide range of both traditional and modernist techniques, including aleatoricism and serial procedures.

[29] The musicologist Edward Green writes that Paus's music "is grounded in tradition, is steeped in the value of careful craftsmanship, and yet, at the same time, is passionate, surprising, original, deeply lyrical, and fervently humanist in its social and political orientation."

[30] Known for his virtuosic and idiomatic writing, Paus has collaborated with some of Norway's finest soloists, including violinists Henning Kraggerud and Arve Tellefsen, saxophonist Rolf-Erik Nystrøm and singer Tora Augestad.

Other collaborators have included film director Sara Johnsen, dancer, choreographer and FRIKAR founder Hallgrim Hansegård, and actress Minken Fosheim.

Paus has set to music a number of poets and writers, among them Dorothy Parker, W. B. Yeats, Oscar Wilde, Siegfried Sassoon, Richard Wilbur, William Shakespeare, Christina Rossetti, Emily Dickinson and Anne Frank, and Norwegians André Bjerke, Jens Bjørneboe, Arne Garborg, Knut Hamsun, Johan Falkberget, Harald Sverdrup and Ole Paus.

Stephen Eddins wrote that Paus's work is "sumptuously lyrical and magically wild, and [...] beautifully captures the alluring mystery and danger and melancholy" of Yeats.

"[32] Paus's The Beauty That Still Remains, based on original text by Anne Frank, was commissioned by the Government of Norway for the official Norwegian commemoration of the end of the Second World War in 2015; released as a studio album by 2L in 2020, it received critical acclaim.

[33][34][35][36] Guy Rickards noted in Gramophone that the work "takes its title from one of the most famous, defiant, and affecting quotes from The Diary of Anne Frank: 'I do not think about all the misery, but about all the beauty that still remains.'

The sentiment of that quote, its focus on the positive in a time of dire peril, is the pillar around which Marcus Paus' extraordinarily beautiful cantata is constructed, encapsulated in the last of its eleven movements, Epilogue, setting those very words in an outpouring of melody that is captivating and heartbreaking in equal measure.

Danny Riley argued that "it’s tempting to view its instrumental pyrotechnics as a remnant from Paus's days shredding guitar in prog rock groups as a teenager.

"[29] In 2017, the album Marcus Paus – Odes & Elegies was released by Sheva Contemporary, featuring his works A Portrait of Zhou, Marble Songs, Shostakovich in Memoriam, Vita and Love's Last Rites, performed by Tom Ottar Andreassen, the Norwegian Radio Orchestra, Henning Kraggerud, Oslo Camerata directed by Stephan Barratt-Due and others.

[41] Albrecht Thiemann, editor of Opernwelt, called the work "a captivatingly orchestrated, spirit-sparkling opus" and "a coup that provides an immense listening pleasure.

The German music critic Jan Brachmann wrote in the Frankfurter Allgemeine Zeitung that Paus's O Magnum Mysterium translates "the harmonious language from soundtracks for mystery thrillers into pious devotion, almost based on the maxim: 'You, Christmas are like a David Lynch film, but with a happy ending and no deaths.

'"[44] In 2018 Julie Kleive and Joachim Kwetzinsky released the album En hellig, alminnelig lek (A Sacred, Ordinary Game) with songs by Paus based on poetry by André Bjerke.

[45] In 2020 Kleive and Kwetzinsky released the album Dypt i forledelsen (Deep in Seduction) with songs by Paus based on poetry by Jens Bjørneboe.

"[47] In 2020, Paus released the song cycle Good Vibes in Bad Times, written for mezzo-soprano Tora Augestad based on texts by Donald Trump reconceptualized as poems.

"[50] Daniel Schweiger described Mortal as "truly thunderstruck in announcing Paus’ symphonically avenging talent to a bigger playing field.

In 2022 the Norwegian Armed Forces commissioned Paus to write a major work to tell the stories of the recipients of Norway's highest honour, the War Cross.