Background: Celtic Frost () were a Swiss heavy metal band from Zurich. They are known for their strong influence on the development of extreme metal. Formed in 1982 as Hellhammer, the band became Celtic Frost in 1984 and was active until 1993. It re-formed in 2001 and disbanded following frontman Tom Gabriel Fischer's departure in 2008.
Context: Celtic Frost's frontman, guitarist and singer Tom Gabriel Fischer, adopted the alias Tom Warrior. With Steve Warrior on bass, he formed one of the earliest extreme metal bands, Hellhammer, in 1981. Steve Warrior was later replaced by Martin Eric Ain - also a pseudonym. The band attracted a small international fan-base, got signed to Noise Records in Germany and recorded their debut EP Apocalyptic Raids in March 1984, now a rare find on eBay or second-hand record stores around the world.  Metal publications were also skeptical of Hellhammer's musical endeavor. Metal Forces loathed the group; that started a long-lasting feud between that zine and Warrior, which kept Celtic Frost from playing in England for a couple of years. Rock Power was not fond of Hellhammer either - they considered it "the most terrible, abhorrent, and atrocious thing 'musicians' were ever allowed to record". In fact, they were "receiving miserable reviews everywhere", Warrior concluded.  Regarding the controversial status of his former band, Thomas said:  Way back in 1984 and 85, when Martin Eric Ain and I recorded Celtic Frost's first two albums Morbid Tales and To Mega Therion, Hellhammer lasted on us almost like a curse. Even though Hellhammer was the very reason we had thought over our goals and conceived the Frost, HH's left-overs kept being mighty rocks in our way. Many voices saw Frost as the same band with just a name-change. The lack of musical quality in HH made it almost impossible for us to get an unbiased reaction for Frost. To make a long story short, it almost killed all our work and dreams.  By May 1984, Hellhammer had disbanded. Fischer and Ain, along with session drummer Stephen Priestly, regrouped as Celtic Frost. Their 1984 debut mini-LP, Morbid Tales was a hit in the underground metal scene, and the band set out on its first tour, through Germany and Austria. This was followed with an EP Emperor's Return. Both early releases are now available on the one CD.
Question: Who else was part of this band?
Answer: Steve Warrior

Problem: Background: Karlheinz Stockhausen (German: [kaRl'haInts 'StokhaUzn]; 22 August 1928 - 5 December 2007) was a German composer, widely acknowledged by critics as one of the most important (Barrett 1988, 45; Harvey 1975b, 705; Hopkins 1972, 33; Klein 1968, 117) but also controversial (Power 1990, 30) composers of the 20th and early 21st centuries. A critic calls him "one of the great visionaries of 20th-century music" (Hewett 2007). He is known for his groundbreaking work in electronic music, for introducing controlled chance (aleatory techniques or aleatoric musical techniques) into serial composition, and for musical spatialization.
Context: On 29 December 1951, in Hamburg, Stockhausen married Doris Andreae (Kurtz 1992, 45; Maconie 2005, 47). Together they had four children: Suja (b. 1953), Christel (b. 1956), Markus (b. 1957), and Majella (b. 1961) (Kurtz 1992, 90; Tannenbaum 1987, 94). They were divorced in 1965 (Rathert 2013). On 3 April 1967, in San Francisco, he married Mary Bauermeister, with whom he had two children: Julika (b. 22 January 1966) and Simon (b. 1967) (Kurtz 1992, 141, 149; Tannenbaum 1987, 95). They were divorced in 1972 (Rathert 2013; Stockhausen-Stiftung & [2013]).  Four of Stockhausen's children became professional musicians (Kurtz 1992, 202), and he composed some of his works specifically for them. A large number of pieces for the trumpet--from Sirius (1975-77) to the trumpet version of In Freundschaft (1997)--were composed for and premiered by his son Markus (Kurtz 1992, 208; M. Stockhausen 1998, 13-16; Tannenbaum 1987, 61). Markus, at the age of 4 years, had performed the part of The Child in the Cologne premiere of Originale, alternating performances with his sister Christel (Maconie 2005, 220). Klavierstuck XII and Klavierstuck XIII (and their versions as scenes from the operas Donnerstag aus Licht and Samstag aus Licht) were written for his daughter Majella, and were first performed by her at the ages of 16 and 20, respectively (Maconie 2005, 430, 443; Stockhausen Texte, 5:190, 255, 274; Stockhausen Texte, 6:64, 373). The saxophone duet in the second act of Donnerstag aus Licht, and a number of synthesizer parts in the Licht operas, including Klavierstuck XV ("Synthi-Fou") from Dienstag, were composed for his son Simon (Kurtz 1992, 222; Maconie 2005, 480, 489; Stockhausen Texte, 5:186, 529), who also assisted his father in the production of the electronic music from Freitag aus Licht. His daughter Christel is a flautist who performed and gave a course on interpretation of Tierkreis in 1977 (Stockhausen Texte, 5:105), later published as an article (C. Stockhausen 1978).  In 1961, Stockhausen acquired a parcel of land in the vicinity of Kurten, a village east of Cologne, near Bergisch Gladbach in the Bergisches Land. He had a house built there, which was designed to his specifications by the architect Erich Schneider-Wessling, and he resided there from its completion in the autumn of 1965 (Kurtz 1992, 116-17, 137-38).
Question: When did he marry Mary Bauermeister ?
Answer:
On 3 April 1967,