Problem: Background: Josef Mengele (German: ['jo:zef 'meNG@l@]; 16 March 1911 - 7 February 1979) was a German Schutzstaffel (SS) officer and physician in Auschwitz concentration camp during World War II. Mengele was a member of the team of doctors responsible for the selection of victims to be killed in the gas chambers and for performing deadly human experiments on prisoners.
Context: The ideology of Nazism brought together elements of antisemitism, racial hygiene, and eugenics, and combined them with pan-Germanism and territorial expansionism with the goal of obtaining more Lebensraum (living space) for the Germanic people. Nazi Germany attempted to obtain this new territory by attacking Poland and the Soviet Union, intending to deport or kill the Jews and Slavs living there, who were considered inferior to the Aryan master race.  Mengele joined the Nazi Party in 1937 and the Schutzstaffel (SS; protection squadron) in 1938. He received basic training in 1938 with the Gebirgsjager (mountain infantry) and was called up for service in the Wehrmacht (German armed forces) in June 1940, some months after the outbreak of World War II. He soon volunteered for medical service in the Waffen-SS, the combat arm of the SS, where he served with the rank of SS-Untersturmfuhrer (second lieutenant) in a medical reserve battalion until November 1940. He was next assigned to the SS-Rasse- und Siedlungshauptamt (SS Race and Resettlement Main Office) in Posen, evaluating candidates for Germanisation.  In June 1941, Mengele was posted to Ukraine, where he was awarded the Iron Cross Second Class. In January 1942, he joined the 5th SS Panzer Division Wiking as a battalion medical officer. He rescued two German soldiers from a burning tank and was awarded the Iron Cross First Class, as well as the Wound Badge in Black and the Medal for the Care of the German People. He was seriously wounded in action near Rostov-on-Don in mid-1942, and was declared unfit for further active service. After recovery, he was transferred to the Race and Resettlement Office in Berlin. He also resumed his association with von Verschuer, who was at the Kaiser Wilhelm Institute of Anthropology, Human Heredity, and Eugenics. Mengele was promoted to the rank of SS-Hauptsturmfuhrer (captain) in April 1943.
Question: When did he join the military?
Answer: Mengele joined the Nazi Party in 1937 and the Schutzstaffel (SS; protection squadron) in 1938.

Background: Tangerine Dream is a German electronic music band founded in 1967 by Edgar Froese. The group has seen many personnel changes over the years, with Froese being the only continuous member until his death in January 2015. The best known line-up of the group was its mid-70s trio of Froese, Christopher Franke, and Peter Baumann. In the late 1970s, Johannes Schmoelling replaced Baumann.
Context: Edgar Froese arrived in West Berlin in the mid-1960s to study art. His first band, the psychedelic rock-styled The Ones, disbanded after releasing only one single. After The Ones, Froese experimented with musical ideas, playing smaller gigs with a variety of musicians. Most of these performances were in the famous Zodiak Free Arts Lab, although one grouping also had the distinction of being invited to play for the surrealist painter Salvador Dali. The music was partnered with literature, painting, early forms of multimedia, and more. It seemed as though only the most outlandish ideas attracted any attention, leading Froese to comment, "In the absurd often lies what is artistically possible." As members of the group came and went, the direction of the music continued to be inspired by the Surrealists, and the group came to be called by the surreal-sounding name of Tangerine Dream, inspired by the line "tangerine trees and marmalade skies" from The Beatles' track "Lucy in the Sky with Diamonds."  Froese was fascinated by technology and skilled in using it to create music. He built custom-made instruments and, wherever he went, collected sounds with tape recorders for use in constructing musical works later. His early work with tape loops and other repeating sounds was the obvious precursor to the emerging technology of the sequencer, which Tangerine Dream quickly adopted upon its arrival.  The first Tangerine Dream album, Electronic Meditation, was a tape-collage Krautrock piece, using the technology of the time rather than the synthesized music they later became famous for. The line-up for the album was Froese, Klaus Schulze, and Conrad Schnitzler. Electronic Meditation was published by Ohr in 1970, and began the period known as the Pink Years (the Ohr logo was a pink ear). But starting with their second album, Alpha Centauri, the group has been a trio or occasionally duo of electronic instruments, commonly augmented by guitar from Froese (or, much later, other musicians as well), and occasionally also other instruments. Of these, drums from Christopher Franke and organ from Steve Schroyder (on Alpha Centauri) or Peter Baumann (on subsequent releases) feature prominently in the band's music during the early 70s. They also started their heavy usage of the Mellotron during this period.
Question: what was krautrock?
Answer:
Electronic Meditation, was a tape-collage Krautrock piece, using the technology of the time rather than the synthesized music they later became famous for.