Question: Which Russian opera singer with a basso profundo vocal range died April 12, 1938?

Context articles: Georgia Brown (Brazilian singer)
Basso profondo
Tex Brashear
Philip Booth (bass)
Feodor Chaliapin
Mahlathini
Georgy Sviridov
Turetsky Choir Art Group
Bass (voice type)
Vladimir Miller

Georgia Brown, pseudonym of Rossana Monti (born June 29, 1980) is an Italian Brazilian singer noted for her extensive vocal range.
 She was listed in the 2005 "Guinness World Records" for hitting the highest vocal note and for possessing the greatest vocal range for a female, claimed to be exactly eight octaves from G-G using scientific pitch notation.
 However, as of 2013, Tim Storms holds the record for the widest vocal range of any human with 10 octaves.
Basso profondo (Italian: "deep bass"), sometimes basso profundo or contrabass, is the bass voice subtype with the lowest vocal range.
Tex Brashear (born January 2, 1955) is a voice actor, who after a career in radio in Texas, Arizona, and Los Angeles, made the transition into voice acting.
 Known as "The Man of 1000 Voices" (although he actually does more than 3000), Brashear has been heard in thousands of cartoons, radio and television commercials, and has narrated many nature and historical films.
 His "basso profundo" voice has been heard in countless movie trailers through the years.
 His comedic singing has even been featured on "The Doctor Demento Show".
 He has also voiced and produced comedy bits for "The Howard Stern Show" and "The Rush Limbaugh Program".
 Winner of 102 Addy Awards, he is also credited with discovering and developing the technique of reverse breathing, a vocal technique used by voice actors to help sustain their long breaths.
 It is somewhat related to circular breathing.
 In addition to voice acting, he has also served as casting director and dialect coach for many films, both American and foreign, and has contributed many research papers on the history of the American Southwest.
Philip Booth (born 1942) is an American operatic bass who is chiefly associated with the basso profundo repertoire.
 Now retired from performance, he was particularly active with the Metropolitan Opera in New York City where he gave more than 400 performances from 1975–1995.
Feodor Ivanovich Chaliapin (Russian: Фёдор Ива́нович Шаля́пин , "Fyodor Ivanovich Shalyapin"; ] ; February 13 [O.S. February 1] 1873 April 12, 1938) was a Russian opera singer.
 Possessing a deep and expressive bass voice, he enjoyed an important international career at major opera houses and is often credited with establishing the tradition of naturalistic acting in his chosen art form.
Simon "Mahlathini" Nkabinde (1938 – 27 July 1999) was a South African "mbaqanga" singer.
 Known as the "Lion of Soweto", Nkabinde is the acknowledged exponent of the deep-voiced, basso profundo "groaning" style that came to symbolize mbaqanga music in the 1960s.
 Nkabinde was also a very active live performer in South Africa, recording and performing with the Mahotella Queens and the backing Makgona Tsohle Band from 1964 to 1971, and then again from 1983 to 1999.
 The Mahlathini and the Mahotella Queens act was propelled into international stardom in the wake of Paul Simon's 1986 "Graceland" album.
Georgy Vasilyevich Sviridov (Russian: Гео́ргий Васи́льевич Свири́дов; his patronymic is also transliterated "Vasil'yevich", "Vasilievich", and "Vasil'evich") (December 16, 1915 – January 6, 1998) was a Russian neoromantic composer, active in the Soviet era.
 He is most widely known for his choral music, strongly influenced by the traditional chant of the Russian Orthodox Church, as well as his orchestral works which often celebrate elements of Russian culture.
 Sviridov employed, in his choral music especially, rich and dense harmonic textures, embracing a romantic-era tonality; his works would come to incorporate not only sacred elements of Russian church music, including vocal work for the basso profundo, but also display the influence of Eastern European folk music, 19th-century European romantic composers (especially Tchaikovsky), as well as neoromantic contemporaries outside of Russia.
 He wrote musical settings of Russian Romantic-era poetry by poets such as Lermontov, Tyutchev and Blok.
 Sviridov enjoyed critical acclaim for much of his career in the USSR.
Turetsky Choir (Russian: Хор Турецкого ) (art group) is a Russian men's a cappella ensemble and musical collective under the direction of Mikhail Turetsky.
 Their voices range from tenore contraltino to basso profundo.
A bass ( ) is a type of classical male singing voice and has the lowest vocal range of all voice types.
 According to "The New Grove Dictionary of Opera", a bass is typically classified as having a vocal range extending from around the second E below middle C to the E above middle C (i.e., E–E).
 Its tessitura, or comfortable range, is normally defined by the outermost lines of the bass clef.
 Categories of bass voices vary according to national style and classification system.
 Italians favour subdividing basses into the "basso cantante" (singing bass), "basso buffo" ("funny" bass), or the dramatic "basso profondo" (low bass).
 The American system identifies the bass-baritone, comic bass, lyric bass, and dramatic bass.
 The German "fach" system offers further distinctions: Spielbass (Bassbuffo), Schwerer Spielbass (Schwerer Bassbuffo), Charakterbass (Bassbariton), and Seriöser Bass.
 These classification systems can overlap.
 Rare is the performer who embodies a single "fach" without also touching repertoire from another category.
Vladimir Miller (Russian: Влади́мир Ми́ллер) is a Russian opera folk, and choir singer possessing a low-ranging basso profondo (oktavist) voice, one of the lowest voices in the world.