'Glee' has unveiled an emotional promo for its Cory Monteith tribute episode.

The hit musical TV show has released the first footage from its tearful homage to the late actor - who died from a combination of heroin and alcohol abuse in July - which is set to the tune of Bob Dylan's 'Make You Feel My Love', performed by Cory's real-life girlfriend Lea Michele.

Producers have decided to kill off Cory's character Finn Hudson and the episode, which airs in the US next Thursday (10.10.13), will see his grief-stricken fellow glee club members come to terms with his death.

The 30-second clip features solemn shots of a sobbing Lea, who plays Finn's on/off girlfriend Rachel Berry, being consoled by Matthew Morrison's Mr. Schuester, while Chris Colfer's Kurt Hummel is seen crying as he clings on to Finn's varsity football jacket.

Discussing the tribute at a Q&A screening of his other show 'American Horror Story' yesterday (03.10.13), executive producer Ryan Murphy admitted most of the scenes were filmed in one shot because the cast and crew found it incredibly tough to shoot the emotional episode.

He said: ''What you will see in the episode is what really happened. Those performances that you'll see, almost everything in that episode is from the first take of every performance because the actors and the crew had a really hard time shooting it.

''I've never seen a crew that you can't continue shooting because they've left the room sobbing. It was very hard. I struggled even working on it because what you're seeing is what they felt not just about Finn but Cory.''

Recovering addict Cory was found dead at the age of 31 in a hotel room in Vancouver, Canada, just months after completing a stint in rehab.