Taylor Swift has announced 'Fortnight' featuring Post Malone will be the first single from her new album

She said on Instagram: "I've been such a huge fan of Post because of the writer he is, his musical experimentation and those melodies he creates that just stick in your head forever.

"I got to witness that magic come to life first-hand when we worked together on 'Fortnight'."

Taylor also announced she and Post - real name Austin Richard Post - would be releasing a music video for the track at 8pm Eastern Time on Friday when the album comes out.

She added alongside a black-and-white image of her with Post: "Honestly can't wait for you guys to hear this song at Midnight TONIGHT and see the video at 8pm ET TOMORROW.

'Fortnight' is the first track on 'Tortured Poets' and only one of two songs to feature another artist - with the song 'Florida!!!' featuring 37-year-old Florence Welch, the other collaboration on the record.

Taylor's announcement came after it was reported her NFL player boyfriend Travis Kelce, 34, has "zero concern" the singer may address past relationships on her new album.

A source told the Daily Mail about Taylor's habit of using past romances as inspiration for her material: "If ('Tortured Poets') is about (her ex) Joe (Alwyn), or anyone - even if it is about him in the future - this is the artist she is and he is in love with her and doesn't pay any attention to be jealous.

"(Travis) understands this is a major part of what makes her the person and artist she is and he is no way looking to thwart the direction she takes."

The insider also insisted Travis is "100 per cent" supportive of Taylor's creative choices.

They added she has apparently explained them all to him and he "loves everything she is doing".

The source went on: "They have talked about the album and what the songs are all about.

"Joe or any of her exes is not of concern to him whatsoever."

Taylor dated English actor Joe, 33, for six years before they split in early 2023, with the couple rumoured to have been engaged.