Having developed a strong love for pop songs, Meredith Quill passed this onto her son, Peter Quill, and gave him a Walkman, which she had created a mixtape for, "Awesome Mix Vol. 1," allowing them to enjoy their shared passion together, listening to the songs she loved.
While waiting to visit his mother at the hospital, Quill was listening to "I'm Not in Love" on his Walkman to comfort him, until his grandfather packed it away in his backpack. Meredith gave Quill another mixtape before she passed, but he never opened the gift, so he wasn't aware of it. When Quill was later abducted from Earth by Yondu Udonta, Quill had his Walkman with him, rendering it one of his few possessions from his home he had, causing him to cherish it even more than just for being special between him and his mother.
For the next twenty-six years, Quill would continue to listen to his Walkman, still with the same passion that he had as a child, and even connecting it to his ship, through an in-built tape deck. While exploring Morag to retrieve the Orb from the Temple Vault, Quill listened and danced around to "Come and Get Your Love." Afterwards, while heading to Xandar, Quill played his walkman through the Milano's tape deck, listening to "Go All the Way."
Impounded and Reclaimed
After Peter Quill was arrested and taken to the Kyln, the items he had on him were impounded, including the Walkman, which one of the guards became intrigued by when "Hooked on a Feeling" started playing. Quill noticed the guard touching his Walkman, and demanded he put it down, but instead the guard put on the headphones to listen to the music. Quill became enraged, but the guard tasered him, and kept the Walkman for himself, which he used to listen to "Magic" while roaming around the prison.
Following a prison break, the guard, who was unaware of what had occurred, was listening to "Escape (The Piña Colada Song)" on the Walkman by himself. Determined to reclaim his most prized possession, Quill found the guard, knocked him out, and took back the Walkman, which Drax the Destroyer noted was an imbecilic thing to do. While heading to Knowhere, Quill reconnected the Walkman to the Milano, and had it playing out loud, with "Moonage Daydream" on as they arrived and flew across the mining colony.
Sharing it with the Guardians
Gamora asked Peter Quill why he would risk his life for the Walkman, so he opened up about his mother, and how she and him would listen to music together, and that he had it on him when he left Earth. Gamora further enquired about the Walkman's function, so Quill explained that it's used to listen to music, and proceeded to put the headphones on her, letting her listen to "Fooled Around and Fell in Love," which she briefly enjoyed before attacking Quill for trying to seduce her.
Before departing to battle against Ronan the Accuser and his forces, Quill listened to "Cherry Bomb" as he got prepared and suited up, along with the rest of the Guardians of the Galaxy. After the Dark Aster crashed on Xandar, the tape deck in the Milano was still in tact, and began playing "O-o-h Child," which Quill used to briefly distract Ronan, by challenging him to a dance off. Although the Milano was destroyed, the Walkman and cassette tape survived.
When Quill finally decided to open his mother's gift for him, he saw that it was a new mixtape, titled Awesome Mix Vol. 2, which he played in the rebuilt ship's tape deck, and the Guardians listened to "Ain't No Mountain High Enough" as they departed from Xandar. Over the next few months, the Guardians would also grow a love for listening to Quill's music, especially Groot, who danced to "I Want You Back" while still growing in a pot.
After being hired by the Sovereign to kill the Abilisk, Rocket Raccoon decided to build a speaker system so they could play music from the Walkman while they worked. However, Drax the Destroyer questioned if it was a priority, whic Rocket attempted to justify because of Quill, be he agreed with Drax. When the Abilisk arrived, the Guardians began battling the creature, while Groot turned on the music, and joyfully danced around to "Mr. Blue Sky," until the speakers were destroyed by Drax.
Whilst departing from Sovereign and heading to Xandar, Quill played "Lake Shore Drive" in the tape deck. After meeting Ego, and being invited to accompany him back to his home planet, Quill brought him Walkman along with him, and listened to "The Chain" as they departed from Berhert. While Rocket and Groot stayed behind on Berhert to repair the Milano, Rocket played and hummed to "Southern Nights," a song he liked, while on watch for any attackers to arrive, and proceeded to fight the Ravagers while it played in the background.
Before arriving at Ego's planet, Quill listened to "My Sweet Lord," and continued to once they stepped out of the ship, but soon turned it off to take in the sight of the planet. While on the planet, Quill played "Bring It On Home to Me" on his Walkman, and he and Gamora danced to it. That night, Ego visited Quill and the two talked about the Walkman, as it played "Brandy (You're a Fine Girl)," which was one of Meredith's favourite songs, with Ego commenting that it was fortuitous.
Destroyed by Ego
Ego decided to unveil his true plans to Peter Quill, but he turned against Ego upon learning he killed his mother. So, Ego forcibly began harnessing Quill's power, and after playing the song "Brandy (You're a Fine Girl)," Ego crushed the Walkman, much to Quill's sadness, which he later used as motive to kill his father.