Born into a family of classical musicians. Her mother is a special education teacher and a very good pianist. Her father, Ferenc Illényi - Katica's first teacher - played the violin at the Hungarian State Opera House and was determined to raise all four of his children as musicians. For Katica and her three siblings - Ferenc, Anikó and Csaba - practising for hours a day was a matter of course from the age of 3 and a half.

At the age of 14 she was accepted to the "Special Talents" class at the Lisz Ferenc Academy of Music, where she was taught by Dénes Kovács. In the meantime she graduated from the Béla Bartók Secondary School of Music.

During her years at the University of Music she played in the orchestras of the Hungarian State Opera and the Erkel Theatre.

In 1991 she received her degree in violin performance from the Liszt Academy of Music.

As a newly graduated violinist, she felt the boundaries of classical musical language were narrow, and she wanted to speak with her whole being. It was then that she decided that she wanted to sing and dance as well as play the violin. So she took voice training and singing became her second instrument besides the violin. She also studied acting, jazz and tap dancing. In the early years of her career, unusually for a violinist, she played leading roles in plays, singing-dancing operettas and musicals, both at home and abroad, in which, of course, violin playing also played an important part. In the meantime, he also became acquainted with the more demanding "lighter" genre of classical music. In jazz, swing and world music, she explores stylistic idiosyncrasies that she has not yet been able to discover through classical music.

From 1996 to 2002 she was the singer-violinist of the Budapest Klezmer Band.

The year 1999 proved to be a turning point in her life, during which she was invited to appear solo on various television shows.

In 2002, she started an independent career. Since then, she has given annual concerts of her own, always with a new repertoire of classical music, jazz and sophisticated light music. Her concerts have included gems from the classical violin repertoire, film scores, world music, as well as well-known jazz and Broadway melodies. The music of Bach, Tchaikovsky, Paganini, Dvořák, Gershwin, Morricone, Michel Legrand and John Williams is featured alongside works by Hungarian composers Bartók, Kodály, Liszt and Leó Weiner.

On January 4, 2014, at the New Year's Concert in the Béla Bartók National Concert Hall of the Palace of Arts, she presented for the first time the mystical instrument called the teremin, which does not need to be touched to be played. Among the very few teremin artists internationally, she is currently the only Hungarian performer in the world who plays this mystical instrument.

https://hu.wikipedia.org/wiki/Teremin

In addition to classical music, she has become committed to high quality popular music, singing, playing the violin, theremin and tap dancing in her solo recitals. She leads his audiences from one musical genre to another with entertaining stories.

Her mission is to entertain, to communicate with the audience (interactive interaction) and to promote quality music.

"In my opinion, it is not true that people don't like classical music, they just don't know it"

With her versatile performances, she proves that there is interoperability between different musical styles, bridging cultures.

Her personality, professionalism, work and popularity enable him to reach a wide social stratum with the works of Hungarian composers, classical music, jazz and sophisticated light music. An important goal of her career is to further increase the prestige and international recognition of Hungarian music culture worldwide.

In 2010, she was elected to the list of artists who represent Hungarian music culture internationally, alongside Zoltán Kocsis, Andrea Rost and Márta Sebestyén.

Her charity concerts raise awareness of our interdependence and the importance of selfless service. Among other things, she participated in the City Mission in Budapest at the invitation of the Catholic Church, in Győr at the invitation of the Evangelical Church and in the work of the International Red Cross.

Member of the Music Section of the Hungarian Academy of Arts since 2014

Citizen of Honour of Kőbánya 2018.

Citizen of Budakeszi 2019.