Prior to becoming a freelance programmer he started to work for Downes, programming his Fairlight CMI, (the ninth one ever made) as the Buggles keyboard player had problems communicating with the machine. When Horn & Downes joined Yes, JJ went on tour with them for three months in the United States of America until they both left the group. After that he went to work for Horn, programming his Fairlight where he would become a vital part of Horn’s production team. The computer programmer found himself working alongside future Art of Noise members, Gary Langan and Anne Dudley. The production team worked on hits for Dollar, before working on ABC’s Lexicon Of Love and the late Malcolm McLaren’s Duck Rock albums.

As a freelance programmer JJ was in an elite group of musicians. He developed his own creative way of making sounds by taking advantage of the CMI’s poor quality audio output and transformed them into new ones by distorting the samples so that they were unrecognisable from the original sound source. Early examples of his pioneering methods can be found on Kate Bush’s 1982 album The Dreaming.

One Thursday night those techniques would change the way that records were made, after a bored Langan asked him to help out with an idea that had JJ sample a discarded drumbeat by Alan White from a recording session of the Yes album 90125. The result of that became the Art of Noise, a two-man side project that became a quintet with the addition Dudley, Horn and ex-NME journalist Paul Morley.

This avant-garde group were the first act signed to Horn & Morley’s Zang Tuum Tumb label and they launched it with a nine track EP entitled Into Battle With The Art Of Noise that musically broke new ground in September 1983 and led to a succession of follow up hit singles and albums for the group over a seven year period.

JJ was also one of the main elements behind ZTT’s phenomenally successful second signing, Frankie Goes To Hollywood with their two huge number one hit singles, Relax and Two Tribes. He, along with Horn, Andy Richards and Steve Lipson were effectively FGTH on those tracks with only the band’s two singers, Holly Johnson & Paul Rutherford performing on those recordings. During his time at the label, JJ was also involved with their debut album Welcome To The Pleasuredome and programming for Propaganda and Andrew Poppy.

Besides achieving a Grammy Award, a Billboard "Best Black Dance Act Award", and a Brit Award nomination as part of the Art of Noise, he continued freelance work as either a programmer, producer or remixer for a number of artists including Endgames, The Hostages, Scritti Polliti, John Parr, Paul McCartney, Billy Ocean, Visage, Godley & Creme, Billy Idol, Nick Kamen, Jean Paul Gaultier and the late Nick Kamen. However his most notable work as a producer were the hit singles Kiss Me by Stephen ‘Tintin’ Duffy, Opportunities (Let’s Make Lot’s Of Money) by Pet Shop Boys and a cover of the Frankie Laine hit Jezebel by Shankin’ Stevens.

In 1987 he set up his own publishing company, JJJ Music. He told Music Technology magazine’s readers that he was looking for new regular music with good structure and that they could send him their demos that weren’t overdone, then he could take care of the production side. In the same issue of the magazine he mentioned that he was working on demos for a solo album, but that project never saw the light of day. On the 10th December that year BBC2 aired a television documentary entitled The Case Of Sherlock Holmes that JJ composed and performed the music for.

After the Art of Noise had ended in 1990, JJ continued to work on various other projects including a 1992 concept album entitled Columbus by the Biographers that told the story of Christopher Columbus. His duties on this production were, producer, arranger, programmer and on one track a narrator with some of the recording done at his own Monsterrat Studios in Berkshire.

In March 1993 an album entitled JJ Jeczalik’s Art Of Sampling was released that featured hundreds of samples. The project came about in 1992 after JJ rang Matthew Wilkinson, the head of the Advanced Media Group to place an order for some CDs. Wilkinson suggested that it would be a good idea if he released one. He agreed, raided his Fairlight archives and transferred the samples onto a DAT before they were mastered to Compact Disc. It was aimed at professional musicians hence the high price of £50, it remained on of AMG's best sellers before being deleted and made available again as a digital download.

Two years later in 1995, JJ launched Art of Silence on his own Axiomattic label with two limited edition 12”s, West 4 and the second,The Giant Remixes in early 1996. In many ways this was a follow-up to the Art of Noise, giving the listener an idea of what that group may have sounded like if they had continued to evolve. The name of this new project may or may not have come from an interview in the 16th August 1986 edition of Sounds, after the interviewer said: “People are bound to say The Art Of Noise haven’t been up to scratch since parting with ZTT, just because of the kudos associated with the label. Although that’s taken a bit of a denting of late.” JJ: “Well, there hasn’t been anything. There’ve been statements like ‘Noiseless ZTT.’.” Anne: “And ‘The Art Of Silence’. We liked that, actually.”

In 1996 more versions of West 4 were released along with an album entitledartofsilence.co.uk that featured people he had previously worked with including Bob Kraushaar, Nick Froome, Blue Weaver, Linda Taylor, Dave Bronze and Paul Robinson. It was named after his official website, described by himself as “the worst website possible”. The album was released in three formats, a limited edition CD + diskette entitled Sound Effects that could only be played on a Mac computer, a double vinyl LP and a standard CD.

Music wasn’t JJ's only activity at that time as he had also set up Touch Music Interactive, an interactive production company and label with video director Will Oakley. Work had started on more Art of Silence material in 1997, a 12” entitledTeach Me, was to be his final release, however Axiomattic released a double A-sided 12” called Into The Sun / Out Of The Fire by Lock which he co-produced with Kraushaar, this was the final release for the label.

JJ retired from the music business and traded on the Stock Exchange as the Art of Trading before turning his hand to teaching at two Oxfordshire schools as the head of ICT until his retirement in 2013. According to an updated AMG review for his sample CD the reviewer said “The last time I spoke to him he was talking about retiring from music because he felt he was getting too old for it now and had already 'bought the t-shirt' so to speak.”