CLEAN : Mamma Mia ABBAs piano up for auction

The video discusses a historically significant piano, originally bought by a Stockholm recording studio in the late 1960s. It played a crucial role in music from 1973 to 1977, featuring in many recordings, including the iconic glissando in 'Dancing Queen'. The piano, in excellent condition, is up for auction, offering a unique piece of pop history with a duplicate keyboard mechanism.

What significant event regarding the piano occurred in the late 1960s?

Which band is associated with the piano mentioned in the text?

What unique feature of the piano is highlighted in the text?

What is being offered for sale at auction on the 29th of September?

Describe the condition of the piano mentioned in the text.