Eleni Hallecker was born in Athens. She studied with a G. Averof and G. Bachauer scholarship at the Athens Conservatory with Professor Zoi Agelastou and at the Orfion Conservatory of Athens with the Austrian professor pianist Max Hallecker. In 1985 at her diploma examinations she achieved the highest distinction, unanimous top marks, first prize and a gold medal from a jury of examiners comprising the distinguished professors and piano soloists: Maria Cherogiorgou, Aris Garoufalis, and Dimitris Sgouros.
She participated actively in master classes taught by the renowned professors and piano soloists: Christopher Elton, Alexander Jenner, Oxana Yablonskaya, Alberto Portugheis. In 1986 she took part in the competition proclaimed by the State Orchestra of Thessaloniki. Having secured the first place she collaborated as a soloist with the State Orchestra of Thessaloniki under the direction of conductor Alkis Baltas, in 1988. She has also collaborated with the State Orchestra of Athens under the direction of conductor Viron Fidetzis, in 2001.
In 1989, she distinguished herself at the Eighth International Beethoven Piano Competition in Vienna. She has given numerous solo piano recitals and chamber music concerts in Greece and Austria.
She has done recordings and recital appearances on Greek and Austrian national radio and television. She holds a solo pianist diploma Pianoforte Performance LGSMD (PPD) with distinction from the Guildhall School of London. In 2000 the recording company Lyra issued a CD with works for solo piano by Beethoven, Chopin and Debussy.