[2][4] He does not come from a family of musicians, although “there was always a piano at home” and his mother and grandmother “played for their own enjoyment.”[3][5] He studied music at the Conservatorio Nacional de Música del Perú with Rosa Basurco and Teresa Quesada;[6] at the American College of Greece in Athens, where he received a Bachelor's degree under Dimitri Toufexis;[3] at the Mannes School of Music, where he earned a Master's degree;[3] and in London with Noretta Conci.

33, of Sergei Rachmaninov.”[9] The Piedmont Post praised Kapelis’ “impressive performance” and hailed his San Francisco debut as “a glorious one,” noting his “use of a full range of technique in rendering the total palette of keyboard colors” and his “passionate heart.”[10] In December 2011, Kapelis and his Greek Myth toured through Japan.

[11] In September 2014, Kapelis’ Greek Myth toured Mexico and was the highlight of the season at the Centro Nacional de las Artes Piano Festival.

[12] Kapelis and his “Greek Myth Recital” were chosen for the transfer-of-power ceremony of the Presidency of Council of Europe from Greece to Italy in 2014.

In 2015, Kapelis toured most of Italy's major concert halls performing the Greek Myth at Rome's Parco della Musica, Milan's Auditorium, Florence's Teatro della Pergola, Palermo's Politeama Garibaldi, Vicenza's Teatro Olimpico, culminating in Venice's Palazzo Labia, filmed for broadcast by the Italian Radio-Television (RAI).

[14] The concerts received wide attention by the national media, including La Repubblica[15] and Il Giornale di Vicenza, which praised “the genius of Kapelis”.

[18] Kapelis has repeatedly expressed his profound admiration and gratitude towards Argerich, describing her as “a force of nature,” stating that “everything she plays seems to come out in a single breath, the emotion and the full power of the music, with no hesitation, no filtering.”[8] With the Berliner Barock Solisten, baroque ensemble of the Berlin Philharmonic, Kapelis has recorded the complete Bach Concertos for solo keyboard and orchestra, to be released in 2025.

In 2012 Kapelis was given the direction of a chamber music festival by the Athens Megaron, presenting Martha Argerich and other distinguished soloists over the course of three days.

The series was hailed by the Press as “a triumphant page in the musical life of the city, as well as in the very history of the City of Athens.”[23] In 2016, Kapelis was put in charge of the chamber music series at the Festival de Lacoste in the South of France, with the mandate to give the festival a more instrumental bent beyond its original operatic and vocal character.

[30] In 2019, Kapelis founded the Greco-Latin Trust in order to help young musicians from countries facing economic difficulties, specifically Greece and Latin America.