melody: specifically, the topmost line or voice
soundscape: an acoustic environment or an environment created by sound
Came across this interesting word called soundscape when reading a review of AR Rehman; the article said his music is influenced by that of Ennio Morricone (of The Good The Bad and The Ugly fame). This single word conveyed how the music of one relates to the other. One of those exquisite occasions when the medium transcends the message.
Listening to the two greats of Tamil music, Ilaiyaraja and ARR, one can immediately sense two different approaches to creating music. For me, Ilaiyaraja is the melody maker and Rehman, the soundscapist.
Both are just segments of a fulfulling musical piece... lyrics and vocalists being other important ones. But seems like the areas of specialisation of both musicians are different. With singers like SPB, Ilaiyaraja revelled in creating soulful tunes and melodies. ARR's focus is on creating a soundscape: choosing the base sounds for the song carefully. Running the risk of sampling bias, here are a few songs:
1) church bells tolling in 'Mukkaala, Mukkabula' - Kathalan
2) the barren effect and sounds in the song describing famine in 'Maari mazhai peyyatho' - Uzahavan.
3) more prominently, the rail tracks in 'Chaiyya chaiyya' - Dil Se
ARR uses brief vocal pieces for opening a song ('Chikku bukku', 'Maargazhi thingal', 'Mettupodu' etc) during which (and for a while after) he does the soundscape before launching into the main vocals.
'Sundari kannal oru' - Thalapathi
'Muthalvanae' - Muthalvan
Both are similarly situated songs of Ilaiyaraja and ARR respectively. Probably it's a misplaced comparison, but the difference between the two is too strong. The first one uses tunes and vocal improvisation of SPB to communicate the full pathos of personal life. In the second, ARR takes it upon himself to build the thick base of sounds to indicate conflict with personal life and leaves the rest of the job to Vairamuthu.
Imagine an artist labouring on a lake, a few trees, shrubs and a distant bird before painting the girl with a pitcher. Thats what ARR does to set the soundscape for a song. But with Ilaiyaraja, the image of the girl with the pitcher is so expressive that you don't have to be told where she stands.