Created by John Broome and Carmine Infantino, the character made his first appearance in The Flash #106 (May 1959).
Hartley Rathaway (alias Thomas Peterson) was born deaf, received assistive technology in the form of hearing implants thanks to research funded by his wealthy father (later it was revealed that the implants were made by Dr. Will Magnus). He became obsessed with sound, and pursued little else in life; experimenting with sonic technology, Rathaway eventually invented a technique of hypnotism through music, and a way to cause deadly vibrations. Growing bored of his lifestyle, he turned to crime as the Pied Piper and frequently clashed with Barry Allen, the second Flash.
After Allen's death during Crisis on Infinite Earths, Hartley retired from crime to become a socialist champion of the poor and underprivileged. He also came out as one of DC’s first openly gay characters, and joked that this was ironic, as he was one of the few villains to have ever "gone straight". He first realized he was gay when he became attracted to Rod Lauren when watching The Crawling Hand. Rathaway becomes a good friend of the Flash, Wally West, and his wife Linda, whom he helps with scientific problems.
Some time later, Piper was arrested for the murder of his parents. Wally was sure Piper couldn't have committed such an act, but Piper himself seemed to believe himself guilty. Wally eventually discovered that the true murderer was Mirror Master. Unaware of Wally's discovery, Piper broke out of Iron Heights and struck a deal of some sort with former Rogue and FBI agent the Trickster. During this time, Flash asked the Spectre to erase everyone's memories of his secret identity, due to his wife suffering a miscarriage from an attack by Zoom.
It was later revealed that Barry Allen had Zatanna tamper with the mind of supervillain The Top, turning him into a hero (the Top had gone on a murderous rampage and Allen believed that this was the only way to stop him from causing more harm). As a hero, the Top went insane over the guilt of his earlier deeds. After Allen had died, Wally received a letter from him asking to restore Top's mind if he ever returned. After Wally had Zatanna restore the Top's mind, the Top revealed that when he had been a hero he had attempted to reprogram many of the other Rogues into heroes as well, including the Pied Piper.
When the 'good' Rogues went after the remaining 'bad', Top returned to undo his brainwashing on the redeemed Rogues. When the Piper battled the Flash, West unmasked himself, triggering a flood of memories of their friendship and causing the Piper to pass out as his mind repaired itself. When he awoke, Piper appeared to be his old self again and came to Linda’s aid. Piper remains the only Rogue to no longer be a villain, save for Magenta. He later had all his charges for murder cleared.
One Year Later, Pied Piper was seen in the pages of both The Flash (Vol. 3), and Countdown teaming with a new group of Rogues led by Inertia. The team of Rogues has him working with his parents' murderer, Mirror Master. Piper reveals to have rejoined the Rogues with a plan of infiltrating them, but when Captain Cold, Heat Wave, and Weather Wizard successfully murder Bart Allen, he and Trickster are forced on the run together. They are pursued by heroes and villains alike - in the form of the Suicide Squad, the Question and Batwoman, Poison Ivy and Deathstroke, and eventually Piper's former friend and the newly returned previous Flash, Wally West. Wally confines the two at the Green Arrow/Black Canary wedding, despite the warnings that Deathstroke is planning an all-out assault at the occasion. The two manage to escape the wedding assault, inadvertently picking up Double Down as a passenger. The trio stop at a diner, only to be attacked by the Suicide Squad. Double Down is captured, but Piper and Trickster, using an invisibility field, decide to follow the Squad and free the other captured villains. After encountering and freeing Two-Face, Piper and Trickster are again attacked by Deadshot, who pursues them relentlessly until he succeeds in murdering Trickster. With Trickster's death, the cuffs activate a 24-hour self-destruct, which Piper is able to delay with his flute. When the train they are on is submitted to a border check, Piper flees into the desert. Delirious from the heat, he begins to imagine Trickster's corpse is talking to him. After severing the hand from the rest of the corpse, Piper is brought to Apokolips by Desaad. Desaad unlocks the shackles, and claims that Piper can channel the Anti-Life Equation and control the planet. Before the Piper can do so, Brother Eye finishes assimilating Apokolips.
Desaad finally gets into Brother Eye's control and convinces Piper to play his flute in order to activate the Anti-Life Equation. Piper agrees to play, but upon hearing that Desaad was the mastermind behind his recent misfortune, in an almost successful attempt to break his spirit and taking control over him, he kills Desaad with a tune. He plays one final time for Brother Eye, a swan song, "The Show Must Go On" by Queen, that blows up the merged entity Brother Eye/Apokolips, with him still trapped inside, apparently left to die. However, he is later seen alive in the streets of Gotham City, saying that if he was allowed to live for some reason, this time he will play on the side of the angels.
Pied Piper returns in the Final Crisis: Rogues' Revenge mini-series. He invades the police precinct, and picks up Trickster's will, which is actually a fake that contains information on the other Rogues, written in invisible ink. Piper later steps into the middle of the fight between Inertia, Zoom and the Rogues, using his flute to paralyze the combatants, and taking the opportunity to revenge himself upon Mirror Master through a kick in the face. Before he can do anything else, Libra appears, and stabs Piper in the shoulder with his spear. Although wounded, Piper is able to contribute in the killing of Inertia by holding him in place for the Rogues with his flute. Piper is later mentioned to have turned himself in to the Central City Police Department.
In the rebooted continuity of The New 52, Hartley is now the conductor of Central City's orchestra, and it is said that he is a 'reformed vigilante.' He later assists Flash and former Rogue teammate Captain Cold against the newly united Rogues.
He is in a romantic relationship with David Singh, the director of the crime lab at the Central City Police Department.
A genius of sonic technology, by the age of sixteen Rathaway had crafted a sophisticated flute capable of hypnotizing anyone within range of its sound. He can make anyone do what ever he wants of them, and can even make himself 'invisible' to the perception of others. Although he focused obsessively on sound-based technology in his early years, he later expanded his scope to more general mechanical tinkering. Initially, he employed his mind control techniques almost exclusively on humans (and occasional animals), but during his incarceration in Iron Heights he became infatuated by the prison's ubiquitous rats and incorporated them into his gimmick, adding another similarity to his legendary namesake. He is able to use nearly anything that can create tones for his sonic manipulations, including touch-tone telephones and grass blade whistles. According to Desaad, Rathaway's power is based on the manipulation of the Anti-Life Equation. Rathaway also employs a number of devices that can generate or amplify sound for destructive or protective purposes.
In the alternate timeline of the Flashpoint event, the Pied Piper is a hero who has had his vocal cords ripped out by Citizen Cold, forcing him to rely on a cybernetic replacement. Pied Piper was also a childhood friend of Wally West. He arrives at Wally's lair and discovers that Wally has been killed by Citizen Cold. Pied Piper takes Wally's place in uncovering evidence of Citizen Cold's true identity. Pied Piper runs in through the sewers and intends to rescue Iris West from the Rogues but was apparently killed by Citizen Cold's exploding ice sculpture. He was later revealed to have survived, and revealed to Iris that Citizen Cold had killed her nephew. After threatening to reveal Citizen Cold's true, criminal identity, Pied Piper was briefly attacked by Citizen Cold, who was then frozen by Iris as payback for what he did to Wally.Pied Piper has appeared in the Justice League Unlimited episode "Flash and Substance." Pied Piper was hanging out in a Central City bar, sitting with Turtle-Man when Batman, Orion and the Flash entered the bar he made a run for it.
An alternate version of Pied Piper appeared in the television series Wonder Woman in the episode of the same name. In the episode, a villain by the name of "Hamlin Rule" (played by Martin Mull) used a flute to hypnotize and persuade women to do his bidding like robbing the box offices of the theaters that he performs at.
Andy Mientus portrays Hartley Rathaway/Pied Piper on The CW's The Flash. He is a former employee and protege of Dr. Harrison Wells, who was kicked out by his own parents when he came out as homosexual. When the particle accelerator exploded, his hearing was enhanced to a superhuman level, which resulted in him being in constant agony. He develops sonicwave weaponry in order to exact revenge on Wells by targeting his new protégé, The Flash, as well as creating implants for himself that serve both as hearing aids that dull sound and discreet weapons. He appears in the 11th and 12th episodes of the series' first season, initially attempting to get revenge on Dr. Wells for ruining his reputation after he attempted to reveal the risk of the particle accelerator exploding. He is captured, but manages to escape, although he reveals before his departure that he has learned what became of Caitlin Snow's fiancé Ronnie Raymond the night of the particle accelerator explosion which ultimately leads to the team learning of Ronnie's circumstances. His parents appear in the episode "Revenge of the Rogues" and he is mentioned by name. Mientus told The Wrap in an interview that he's open for a spin off of his character. Cisco later uses the components of both Rathaway's and Sara Lance's (Canary) sonic weapons to develop an ultrasonic collar for the latter's sister Laurel Lance (Black Canary), providing her an artificial ultrasonic ability when wearing it. Pied Piper made another appearance in The Flash episode "Flash Back" where Barry goes back in time to talk to Dr. Harrison Wells/Eobard Thawne about getting faster to defeat Zoom. Barry goes back to Pied Piper's first appearance in the show. This time Barry prevents Hartley from breaking out by having Cisco look closer at Rathaway's implants. Rathaway assists the team in stopping the Time Wraith that's chasing future Barry with his technology, causing Cisco and Caitlin to see him differently. When Barry goes back to the future, he is saved from the Time Wraith by a reformed Hartley. A ramification caused by Barry's time traveling was that Hartley was no longer a villain and was now an occasional aid to Team Flash. His relationship with his parents also appears to be improved.
In Supergirl's crossover episode "Worlds Finest", Pied Piper was mentioned by Barry when he was helping Supergirl develop earpieces similar to the ones he used against Hartley (prior to the timeline's alteration) for the confrontation with new villain Silver Banshee.
Pied Piper appears in the animated film Justice League: The Flashpoint Paradox, in a non-speaking role. In the distorted Flashpoint timeline, Pied Piper is a superhero member of Cyborg's group to stop the war between Aquaman's and Wonder Woman's forces.
Pied Piper appears in DC Universe Online, voiced by Jim Canning.