Record producer Pete Waterman, who worked with Summer in the 1980s, said his abiding memory was of "a lovely person."
The singer teamed up with Stock Aitken Waterman in the late 1980s.
Whenever you were with her she made you feel so special. She had all the talent but she gave you all the credit. She was not a diva in any shape or form.
She was in the wilderness when we had the biggest record of our careers together.
They warned us against working with her because of the whole anti-gay thing that had happened.
But what a voice she had.
She used to warm up in the ladies toilet and everyone in our building would stop and it would come to a standstill to hear her warm up.
More top news
The Prince has called for "zero tolerance" on the ivory trade, which he says is increasing "alarmingly".
A memorial service has been held at Birmingham Cathedral to remember the victims of the Birmingham pub bombings 40 years ago tonight.
One of the world richest and most influential philanthropists has told ITV News that governments failed to act fast enough over Ebola.