Some music is written with 'block' chords, some has weaving parts around the tune, and some music has no harmony at all. These are all examples of textures in music.
A melody and accompaniment texture is when you can clearly distinguish between the melody and accompaniment. This could be a pop song with a solo singer accompanied by a band or the first violins in an orchestra playing the melody while the rest accompany. The melody and accompaniment texture was used frequently in the Classical period.
Listen to the opening of Mozart鈥檚 Symphony no. 40 in G minor:
You can hear that the first and second violins are playing the melody while the lower strings play an accompaniment. This is a typical melody and accompaniment texture.
A song with piano or guitar accompaniment also has a melody and accompaniment texture.
Other textural devices
Countermelody
A countermelodyA secondary melody. is a secondary melody that is sung or played in counterpoint with the original melody. This happens a lot in fugues.
Descant
This is when an additional melody is sung or played over the top of an existing texture. This often happens in the last verse of traditional Christmas carols, when the sopranos are given a higher melody to sing.