A few comments bt Benny about some of the songs from the past.
HEY HEY HELEN (ABBA 1975)
" This would fit on "ABBA WOOD" .. the worst of ABBA, thus, unlike "ABBA GOLD".
" We didn't really know what we wanted to be... Somewhere we believed that it was a bit more trendy with rock'n'roll, and then we did these rock songs that aren't good at all. On the "Waterloo" record we had  horrible songs named "Watch Out", and "King Kong Song". Björn sang some of them, but he thinks similar about this.
SUNNY GIRL (Hep Stars 1966):
" It's too successful", I thought back then.
 I wrote it at a hotel in Kongsvinger, Norway while the Hep Stars were touring."
It sounds very much like Benny Andersson, a lively melody in major.
" No. I didn't know  much English, so I had to write it with a dictionary in my hand. There was a line that was a misunderstanding."
"To write lyrics was hard. I started making the rhymes in the end of the text lines, and afterwards filled in, so to speak, backwards".