The buskers favourite, Here Comes The Sun by The Beatles
others worth checking out
In The Summertime by Mungo Jerry “If her Dad is rich take her out for a meal, if her Dad is poor just do what you feel” classic lyric
Summertime by Will Smith “the weather is hot and girls are dressing less” another great lyric
Far From Home by The Levellers “It’s warm by the river, the weir keeps us clean
The woodsmoke and cigarettes are all that we need” just conjurers up a nice image
Surfin’ USA by The Beach Boys “bushy bushy blonde hairdo” need I say more
True Faith by New Order “I get this feeling Im in motion A sudden sense of liberty” that’s how the summer makes me feel and it’s an all round gorgeous song
The Sea by Morcheeba “I left my soul there Down by the sea I lost control here Living free” another nice image
There She Goes by The La’s, actually a song about drugs but I think you will agree it has a sunny disposition
Bye Bye Badman by The Stone Roses “In this citrus sucking sunshine I dont care” again a song that has nothing to do with summer but the whole sound is jolly even if the meaning isn’t
Hope you enjoy these suggestions