Between 2017 and 2021, Jan Stoklosa served as Music Director of the Musical Stage at the Rampa Theatre in Warsaw, where he led some of its largest productions, including Rhapsody with the Demon, Broadway Exclusive, Women on the Verge of a Nervous Breakdown, Twist and Shout, and Jesus Christ Superstar.

He co-created music for three commissioned productions by the Grand Theatre – National Opera in Warsaw: Impressions(2013), Love Dilemmas after Krakowiacy i Gorale (2015, marking the 250th anniversary of the National Theatre), and A Midsummer Night’s Dream (2017). He was also the arranger and conductor of the I Love Moniuszko project (2019).

As a composer for musical theatre for children, he created Only Behave! (Tylko Grzecznie, 2024, Musical Theatre Gdynia) and The Ugly Duckling (Brzydkie Kaczatko, 2025, Theatre Zaglebia).

In 2023, Stoklosa served as Music Director, principal composer, arranger, and conductor of the Opening Ceremony of the 3rd European Games in Krakow.

He has a long-standing collaboration with the Film Music Festival in Krakow (FMF), for which he has created and arranged numerous gala concerts: Scoring4Wajda (2015 – selected arrangements), The Glamorous Show (2019 – music direction and arrangements), Film Music Gala (2021 – selected arrangements), Scoring4Skolimowski (2022 – orchestral suite and conducting). He also led recording sessions, lectures, and served as a juror at the FMF’s Young Talent Academy (2023–2025).

Stoklosa collaborated with the Podlasie Opera and Philharmonic, where he served as Music Director and conductor for the musical Jesus Christ Superstar (2020–2024), and as arranger for the musical fairy tale Puss in Boots (2016).

He has led numerous television productions as music director, arranger, and conductor, including:
Ministry of Culture Awards Gala (2019, 2023), (Un)Forbidden Songs – annual concerts for the Warsaw Uprising Museum (2018–2025), In the Year Nineteen (for the 100th anniversary of the Silesian Uprising, 2019), Pelplin Cathedral Christmas Concerts (since 2016), Battle of Tenors for the Rose (2020–2022), Feniks Gala (2020), Great Christmas Carols with Polsat (2022), Two Theatres Festival (2022), Four Sides of Folk Festival (2023), Who Calls Us – 70 Years of GOPR(2024), Birthday in Europe – 20 Years of Poland in the EU (2024), Polsat Earth Festival (2024), Carols under the Tatras(2024), Polsat Hit Festival in Sopot (2025), Debuts Concert at the 62nd National Polish Song Festival in Opole (2025), Songs Across Four Corners of the World (closing concert of the Polish EU Presidency, 2025), Our Solidarity – We Made It! in Gdansk (2025), and the 50th Polish Film Festival Awards Gala in Gdynia (2025).

From 2017 to 2019, he was Music Director, arranger, and conductor of the concert series and nationwide tour Gintrowski – Something Will Remain After Us.

As orchestrator and conductor of the acclaimed project Miuosh x Slask – Contemporary Songs (Piesni Wspolczesne, 2021), he contributed to a double platinum album that earned two Fryderyk Awards: Roots/Blues Album of the Year(2022) and Music Project of the Year (2023). The live concert version, Live at Cavatina Hall, achieved gold record status. In 2024, Contemporary Songs Vol. II was released.

He collaborated with the metal band Behemoth, composing and conducting orchestral parts for two of their albums: I Love You at Your Darkest (Fryderyk Award – Metal Album of the Year 2019) and Opvs Contra Natvram (Fryderyk Award – Metal Album of the Year 2023).

In 2024, he created new orchestral arrangements for Fisz Emade Tworzywo Symfonicznie, performed live across Poland with the Stoklosa Collective Orchestra.

In 2017, he arranged symphonic versions of Beata Kozidrak’s greatest hits for Ferrero Roche and Sinfonia Viva.
In 2018, he composed music for poems by Kazimiera Illakowiczowna, resulting in Natalia’s EP The Rebellion of Youth.
In 2020, he arranged and produced There is a Star, an album of Sophia Loren’s songs broadcast on over 40 Italian radio stations.

As a composer for radio and podcasts, he wrote music for The Unconquered 1920 (Polish Radio 2, dir. Emilian Kaminski, 2020) and The Extraordinary Ones – a series about heroes of the Greater Poland Uprising (dir. Adam Wojtyczko, prod. Gabriela Guszczyn-Poplawska).

He has frequently collaborated with Andrzej Smolik as orchestrator and instrumentalist on projects such as Miuosh/Smolik/NOSPR, Obywatel GC 2.0, Histories (Warsaw Uprising Museum), Nina (film), and Sopot 120th Anniversary Gala.

He created orchestral arrangements for the 25th Anniversary Tour of Justyna Steczkowska (2021–2022).
He co-produced the new soundtrack for the musical Metro, premiered during its anniversary show at Spodek Arena in 2021.
He composed the official anthem for the World Athletics Relays (Chorzow, 2021).

As Music Director of the 28th IHF Men’s World Championship Draw Gala, he conducted the NOSPR Orchestra in Katowice in his own symphonic arrangements of popular songs — broadcast in over 120 countries worldwide.

In March 2022, together with the band IRA and his Stoklosa Collective Orchestra, he launched the charity initiative Music of Freedom, featuring a new orchestral arrangement of Obejmij Mnie, created in collaboration with the Ukrainian band Okean Elzy. The video, viewed by millions within days of release, raised funds for humanitarian aid to Ukraine.

As part of the Polish Composers’ Program, he wrote Folk Variations (Wariacje Ludowe) — a concert for string orchestra, ethnic instruments, and voices. The piece was commissioned by Sinfonietta Cracovia and premiered at the EtnoKrakow/Rozstaje Festival in 2022.

In 2022, he also composed Three Romantic Pieces, based on Adam Mickiewicz’s Ballads and Romances, commissioned by the National Centre for Culture. This three-part ballet suite (Primrose, The Nymph of Switez, Pan Twardowski) was written for 12 solo instrumentalists.

He served as music producer of the album One Heart – (Con)texts of Polish Romanticism, featuring settings of poems by Polish poets, including new compositions by Stoklosa alongside works by Niemen, Grechuta, and Moniuszko. Performers included Kasia Mos, Mateusz Ziolkowski, Olga Szomanska, Janusz Radek, Lukasz Drapala, and Rafal Bartminski (2022).

His film scores include Rotmistrz Pilecki (dir. Milosz Kozioł, 2022) and Niejadek (dir. Ewa Japola, 2023).

In 2023, he was Music Director of The Musical History of Film Lodz concert, for which he created new orchestral arrangements of classic film scores from the Lodz Film Studio catalogue. Featured artists included Zbigniew Zamachowski, Janek Mlynarski, Julia Pietrucha, Natalia Grosiak, and Lukasz Lach, accompanied by the Stoklosa Collective Orchestra.

Later that year, he co-created the special concert The History is Now with Tribbs at the Polish History Museum in Warsaw.

He co-arranged, orchestrated, and conducted the monumental concert Katopolis (2023), marking Katowice’s inauguration as the European Capital of Technology. The performance featured over 250 artists, including the Stoklosa Collective Orchestra, FDG Orchestra, and a combined choir of nearly 180 singers from Silesian universities, as well as soloists Natalia Szroeder, Krzysztof Zalewski, Mela Koteluk, Natalia Grosiak, Piotr Rogucki, Igo, and Dawid Tyszkowski.

In 2024, he orchestrated and co-arranged with Miuosh the concert Krakow Creates Metamorphoses, celebrating the 10th anniversary of Tauron Arena. The program included new symphonic versions of songs by Kora, Wodecki, Grechuta, and Zaucha, performed by the Beethoven Academy Orchestra under Stoklosa’s baton, featuring artists such as Krzysztof Zalewski, Kacperczyk, Mery Spolsky, Renata Przemyk, Kuba Badach, Grubson, and Igo.

Between 2021 and 2023, he led the original composition and arrangement workshops WarsztatON at the Grand Theatre – National Opera in Warsaw.
He has served as juror at the 69th Eurovision Song Contest (2025) and at the National Festival of Musical Arrangement “AranzacJA Fest” in Kalisz (2024–2025), where he also led masterclasses.

In 2018, he was Music Director of the highly acclaimed concert Best of Broadway at the Polish Theatre in Warsaw, featuring world-renowned musical theatre star Ramin Karimloo.

He is co-composer and arranger of music for children’s theatre productions including The Devoured Princess Bluetka and See the Zoo (based on poems by Jan Brzechwa).

As composer of Christmas music, he regularly contributes to the charity concert series Christmas as a Gift (Swieta w Prezencie), performed annually at major Polish venues including the Fryderyk Chopin University of Music, Polish Radio Studio S1, and the National Philharmonic.

Stoklosa is also an active composer of classical music, often writing commissioned works for ensembles such as Hornet Quartet and the Sinfonia Varsovia String Quintet.

He has collaborated with leading Polish orchestras including NOSPR, NFM, Sinfonia Varsovia, the Beethoven Academy Orchestra, the National Opera Orchestra, the Baltic Philharmonic, and the Szczecin Opera.

Formerly a cellist of the Fair Play Quartet, specializing in pop music arrangements for strings and performing worldwide, he also played with Sinfonia Iuventus and the National Opera Orchestra in Warsaw.

As a session musician, he appears on over 60 recordings, collaborating with many of Poland’s top artists.
He is a laureate of numerous national and international classical music competitions, both chamber and solo (as a cellist).

In 2025, Jan Stoklosa received the “Proud of the Insurgents” Award (Dumni z Powstancow).