Neutral Milk Hotel was an American indie rock band formed in Ruston, Louisiana by singer, guitarist, and songwriter Jeff Mangum in the late 1980s. The band is noted for its experimental sound, abstract lyrics and eclectic instrumentation. The first release under the Neutral Milk Hotel moniker was the 1994 EP Everything Is, a short collection of tracks featuring Mangum.
Origins
Jeff Mangum, along with high-school friends Will Cullen Hart and Bill Doss, formed The Olivia Tremor Control, with Mangum appearing on their first release, the California Demise 7".  Prior to recording for friends under the Neutral Milk Hotel moniker, Mangum recorded a few cassettes under the name Milk; the most well-known of these tapes was called Pygmie Barn in E Minor. These are the earliest known recordings that Mangum initiated and executed himself. There were only an estimated dozen or so copies ever made of this tape, none of which has been made public. It was revealed c. 2006 on the Elephant 6 online forums that another tape under said name, entitled Beauty, was released, along with several recordings under the name Ruby Bulbs (also a song dating from that era, perhaps the only Milk song to be played by Neutral Milk Hotel).  Neutral Milk Hotel began simply as a recording project for Mangum, in the late 1980s. He produced several demo cassettes, among them 1991's Invent Yourself a Shortcake, 1992's Beauty (not to be confused with the earlier cassette), and 1993's Hype City Soundtrack, along with two more from this period, seemingly unnamed. Although easily found on the Internet, these demos capture the project at a very embryonic stage: songs are played in between various sound collages and tape experiments, one of which consists only of a six-minute conversation between Mangum and Hart. Another track, "Digestion Machine", features a varied collage of voices answering the question asked by Mangum, "What does the digestion machine mean to you?". The more accessible "Synthetic Flying Machine", also titled "Up and Over", later became "The King of Carrot Flowers Pt. 3" on In the Aeroplane Over the Sea.  During this period, Mangum was wandering the country, staying with friends, and in a state of perpetual unemployment. It was in these circumstances that the band's first formal releases took shape. Strictly speaking, however, the 'band' usually consisted of Mangum and whoever else was present at the time. This is obvious on Neutral Milk Hotel's first release, a 7" record entitled Everything Is, recorded when Mangum was spending time in Seattle, Washington, released on Cher Doll Records in 1993.

Q: what are their origins?
A: Jeff Mangum, along with high-school friends Will Cullen Hart and Bill Doss, formed The Olivia Tremor Control,

Q: what was their first  release?
A: Mangum appearing on their first release, the California Demise 7".

Q: did they have a different name when they started?
A: Neutral Milk Hotel moniker, Mangum recorded a few cassettes under the name Milk;

Q: what were some of these casettes called?
A: 1991's Invent Yourself a Shortcake, 1992's Beauty (not to be confused with the earlier cassette), and 1993's Hype City Soundtrack,

Q: did they produce any hits?
A: unknown
what other songs were on the cassettes?
Another track, "Digestion Machine",
Another track, "Digestion Machine",