I'm interested in compiling a collection of songs that made the UK or US
top 40 during the 70s that were purely instrumental (ie featured no
vocals at all - that rules out the likes of Walk In The Night by Junior
Walker, Pick Up The Pieces by Average White Band or even TSOP by MFSB).

So far I have:

Feels So Good - Chuck Mangione
Magic Fly - Space
Morning Dance - Spyro Gyra
Music Box Dancer - Frank Mills

I can't even think of a 5th song - I'm sure there is one!