people rally place desert to leave with alliens

[Ron Wolpa]

I can recall not so much about the movie :
• it is an early 1970s USA production
• knowing that alliens , who never are shown in the movie , are going to take people to a new style of live in a better place , people from everywhere rally to a place in desert , where there is a kind of tent ; despite many people walk into the tent , that is not large , it does not seem to get cramped up.
• some who come with their wife or husband happen to quit the adventure a few steps from the tent.
this is the case of an old man who came with his wife , she goes into the tent , but he decides against.
just a little before this he had sold his car to an opportunist salesman who was there to profit over people who will departure , as they would not need it any longer their cars.
As he has not gone he tried to cancel the deal and get his car back , but the opportunist is adamant.
• a young couple arrives , he is a professional flutist who came together with his girl in the attempt to make her change her mind. She doesn´t and goes into.
... ...... can´t remember exactly . ??... it is already night , all the people and the tent are gone , he is by himself then lights approach flying in his direction blinding him for a second , time enough to whom watches the movie to be in doubt whether the alliens are back.
It is a airforce helicopter that picks him up.
• movie ends with him playing flute in a bandshell , he looks to the night sky to find out whether some stars are in a certain position , because "they" get back when it happens and he wants to be ready for them.
Which movie is this ??
Thank you for your attention.

[astrakhan]

Close Encounters of the Third Kind?