‘Kayleigh’ was by Marillion (not Merillion) and was released as a single here in the UK. It was their most popular hit, which isn’t actually saying much as they rarely troubled the singles charts or, to be fair, wanted to.
The ‘Blow away, blow away, blow away’ song by George Harrison is from his 1979 album simply titled ‘George Harrison’, and the track itself is called… er… ‘Blow Away’.
As for the OP, I could go on all night. I seem to have a rich treasure house of specific songs that no-one else I know has ever heard of, let alone heard.
An obscure and not terribly successful band called ‘Moon’ released a not-very-good album which contained one diamond gem called ‘I’m Leaving You’, being a soulful, touching and heart-warmingly track as gorgeous as anything else in popular music. I think I still have it on vinyl somewhere, although I have no machine to play it on, and it deserves to be more widely heard.
1970s prog rock dinosaur Mike Oldfield once released an album called ‘Platinum’. On side 2 (in those days, kiddies, they had sides) there was a song called ‘Sally’, which was gloriously silly and playful. The album, silly song notwithstanding, duly went on sale. However, the record company objected to the puerile silliness of the song, and insisted MO replace the silly version with a more ‘normal’ version. He did so, and the album was duly relaunched. Only myself and a few other die-hard MO nuts at the time snapped up the album before the ‘silly’ song was replaced, and consequently very few people have ever heard it. This is a shame only because it is so deliciously silly and entertaining, and a stark antidote to the rather morose and serious profile Oldfield had at the time.
When Alex Harvey was in traction in hospital with a badly injured back, the other four members of ‘The Sensational Alex Harvey Band’ recorded an album called ‘Fourplay’. Rather mediocre dreck for the most part, but one track, ‘Love You For A Lifetime’, was actually very good. I’ve enjoyed listening to it for years, and it’s a very good Valentine song as well.
I could go on… but I won’t.