Dukwon Seo (서덕원) is a South Korean jazz drummer, composer, arranger, producer and teacher who has led the trio Gentle Rain (젠틀레인) since he formed it in 2004. He is known by three spellings of the same name: Dukwon Seo on his YouTube channel and on his Zildjian and Vic Firth artist pages, Seo Dukwon on Discogs, and Seo Duk Won on his Pearl Drums page. Korean Wikipedia gives Seoul as his birthplace and carries no birth date, and no other source found states either. He studied Russian at Hankuk University of Foreign Studies and went on to a graduate degree in practical music at Myongji University's graduate school of culture and arts, according to the same article. His sponsors' biographies say he has played with many jazz bands since the mid-1990s and appeared on a long list of recordings and live sessions.

His reputation rests on Gentle Rain more than on any single sideman credit. The trio made its debut album, Into the Gentle Rain, in December 2005, followed by the 2007 film-song album Cinema in Jazz (credited to the Sonagi Project, which Korean sources count as the group's 1.5th album), then Second Rain (2008), Dreams (2010), Wish (2012), Home (2015), Sunlight (2020) and Theme Park (March 5, 2025), the last timed for the trio's twentieth anniversary. Seo is credited as drummer, composer, arranger and producer, and he plays chimes, rain stick, shaker and finger cymbals on several tracks. The sponsors' own pages give different counts (Pearl says six albums, Zildjian and Vic Firth say five), while Korean Wikipedia lists seven numbered studio albums plus the project album. The seventh, Theme Park, was announced by Yonhap on February 27, 2025, and the trio played its release concert at the Guro Arts Valley Theater in Seoul on March 29, 2025.

The line-up has changed twice around him. On Second Rain and Dreams the pianist was Song Ji-hoon and the bassist Lee Wonsool, whom the release notes describe as newly arrived for the second album. From Wish in 2012 the bassist is Kim Ho-cheol, and Song Ji-hoon is still the pianist in 2015. By Sunlight in 2020 the pianist is Choi Han-geul, and the trio of Seo, Kim and Choi made Theme Park. Each member writes for the group; Seo's own pieces include "Second Rain", "Beauty Sleep", "Dream Maker", "Strawberry Juice", "Way to Home", "Joyfully", "Late in the Summer" and "Swing Ride".

In 2011 the readers of the Korean magazine Jazz People (재즈피플) chose him as the country's best jazz drummer in their annual Leaders' Poll. The Weekly Hankook reported that about 3,000 fans voted online and offline over two months across six categories, and that the winners played a project concert at LIG Art Hall in Seoul on June 24 and 25, 2011, the fifth edition of the series. He is also an author. Jazz Rhythm (Score, August 2014) is a rhythm textbook, and Jazz Drum Bible (Modu-ui Eumak, February 2022) followed it. Pearl says he has taught at universities for more than twenty years, and Korean Wikipedia lists a visiting professorship at Myongji University's graduate school of culture and arts, lectures at Dongguk University and an adjunct post at Mokwon University.

Before and alongside Gentle Rain he worked as a sideman. Korean Wikipedia names the trios of Park Ji-hyuk (박지혁), Yang Jun-ho (양준호), Lee Young-kyung (이영경) and Won Young-jo (원영조), the group Interplay, Jung Sung-jo's quintet, Shin Kwan-woong (신관웅)'s New Trio and Lee Jeong-sik (이정식)'s quartet, and recording and live work with pop and crossover singers including Yoon Bok-hee, Insooni, Nah Youn-sun, Park Seong-yeon, Woongsan and Malo. These are listed without dates or catalogue numbers, and Discogs holds none of them under his name. He is not the baseball player Seo Duk-won, who was born in 1993.

In the questionnaire on his Zildjian page Seo answers the question about inspiration with jazz musicians in general and names the drummers Max Roach and Peter Erskine and the bandleaders Pat Metheny and Keith Jarrett. His advice to younger drummers there is to listen to a lot of music and practice a great deal. No lengthy interview in which he explains his approach was found, so the rest of this section sticks to what the records and their notes show.

Gentle Rain plays acoustic piano trio jazz built on clear melodies, and the release notes call the result Korean-style romantic jazz. They also quote the critic Ha Jong-wook, who described the trio's phrasing as jazz that reads like an essay, with a clear opening, development and close. The records mix originals with remakes of pop songs, film themes and classical or folk tunes. Billy Joel's "Just the Way You Are", John Denver's "Sunshine on My Shoulders", Chuck Mangione's "Consuelo's Love Theme" and Stanley Myers's "Cavatina" are on Second Rain, and Wish has a reggae-rhythm "Amazing Grace" and a three-beat "Raindrops Keep Fallin' on My Head". Home arranges the piano duet "Celebrated Chop Waltz", known in Korea as the chopsticks march, with funk and Latin rhythms, and the notes for "G.R. Funk" say the aim was a funk tune that stays polite and elegant. The trio's own notes say that on Theme Park the "Dark Eyes" arrangement pays tribute to a technique from Michel Legrand's "I'll Wait for You".

Seo adds small percussion to several tracks, and the personnel lines name shaker, wind chime, rain stick, finger cymbals, chimes and ocean drum. The trio's notes aim the music at general listeners as well as jazz fans, and the 2015 Kyunghyang piece repeats the claim that Gentle Rain sold more records than any other Korean jazz band, without giving a sales figure.