For the most part, the texture of the song is homophonic or melody and accompaniment. The lead vocals are clearly the main melody of the whole song (with the exception of the electric guitar during its solo) and this dominates the texture. Other parts and melodies are less significant in importance:
The piano plays the chords.
The bass guitar plays the bass line. There are moments where John Deacon takes some more interesting melodic fills for contrast and variation e.g. bar 38 (1'14).
The backing vocals are often sung in parallel harmony with the lead vocal to add emphasis to the melody and lyrics. This is done very clearly in each chorus. There are times when the backing vocals sing different melodic material to the lead vocal providing some polyphony e.g. bars 31-34 (1'00). There are also moments of antiphony or call and response like in bar 36 (1'11) with the word "nat'rally". This textural variety adds to the vibrancy and energy of the music.
The electric guitar overdubs also often play in parallel harmony but often create polyphony with the lead vocal. A good example is the third chorus (bars 70-74, 2'17) where two guitars in harmony play a counter melody that contrasts playfully with the lead vocal. The three guitars also play polyphonically during the guitar solo (bars 55-56, 1'48) and during the outro (bar 79, 2'41) where three different ideas are heard simultaneously to produce quite a chaotic and busy texture at the closure of the song.
David Bowie was incredibly influential during the 1970s as a glam rock artist. This song was released in 1969, the same year Neil Armstrong walked on the moon. It is about a fictional character, Major Tom, travelling into space. It portrays the excitement and mystery of space travel. At the same time, you could also argue that it depicts a certain degree of anxiety and fear of the unknown.
Like Killer Queen, the texture of the song is also primarily melody and accompaniment. Here are some other notes of interest in the texture:
From 0'40 an overdubbed vocal is heard in octaves with the lead vocal. Rather than producing a wholesome harmonic sound, this leaves the texture sounding quite barren, helping to create the sense of nervousness as Major Tom is setting off. Other two part harmonies are heard between the vocals later in the song.
The chorus is heard from 1'27. Strings accompany the chorus alongside drums and acoustic guitar. The parts generally play held notes which bring out the prevailing chord (although the bass guitar is very active and playful with the lead vocal) so the texture remains homophonic.
The simplicity of the texture in the music allows the song's pecularity to come across with a greater degree of clarity.