line taken from the song 'wish you were here' by english rock band pink floyd.part of the original text is:

So, so you think you can tell Heaven from Hell?
blue skies from pain?
Can you tell a green field from a cold steel rail?
A smile from a veil?
Do you think you can tell?
And did they get you to trade your heroes for ghosts?
Hot ashes for trees?
Hot air for a cool breeze?
Cold comfort for change?

Pink Floyd is a progressive rock band, formed in 1964, famous for its songwriting, psychedelic and harmonic classical rock compositions, bombastic style and elaborate live shows. it is one of the most successful acts in the history of rock music.'Wish You Were Here', released in 1975, is a theme album about absence. In addition to the classic title track, the album includes the mostly instrumental 'Shine On You Crazy Diamond', 'Welcome to the Machine' and 'Have a Cigar.'Rolling Stone Magazine has called the cover to 'Wish You Were Here' one of the best album covers ever created. it depicts two business men shaking hands, one of them being on fire.[many thanks to Ristar*jr. on our forum for providing this information].