Many of the tracks on the album were recorded with soft "attacks" of each note, then played backwards, with multiple heavy echoes and reverb added in both directions to merge the notes into one long flowing sound with each note greatly overlapping each adjacent note, producing the "floating" effects that Eno desired.
Eno used the [[YamahaDaniel DX7Lanois]] synthesiserhas extensively<ref name="hyperreal-indie"/> However, it's also been said by engineer [[Daniel Lanois]]stated that a [[Yamaha CS-80]] was used on "Deep Blue Day".<ref>[https://gearspace.com/board/interviews/1363141-interview-daniel-lanois.html Gearspace: Interview with Daniel Lanois]</ref> Eno once stated regarding the soundtrack: "...so many processings and reprocessings – it's a bit like making soup from the leftovers of the day before, which in turn was made from leftovers..."<ref>{{cite magazine|url=http://music.hyperreal.org/artists/brian_eno/interviews/sos2.html|magazine=Sound On Sound|date=February 1989|first=mark|last=Pendergast|title=Brian Eno: "A fervent nostalgia for the future"}}</ref> Eno said, ".... Well, I love that music anyway .... what I find impressive about that music is that it's very concerned with space in a funny way. Its sound is the sound of a mythical space, the mythical American frontier space that doesn’t really exist anymore. That's why on Apollo I thought it very appropriate, because it's very much like '[[space music]]' — it has all the connotations of pioneering, of the American myth of the brave individual...."<ref name=SOS/>
