Ian Arthur Plansker (b. 2003) is a versatile keyboardist, composer, and conductor currently based in Amsterdam and Paris. He is an active ballet and opera répétiteur and is the conductor and artistic director of Orchestra Lagrandt.

Plansker is originally from Detroit, Michigan where he grew up in a musical household—his father is a jazz pianist and his mother a ballet teacher. Plansker’s first instrument was the flute, which he studied with Sharon Sparrow of the Detroit Symphony Orchestra. Later, he became interested in the harpsichord and historical performance. He regularly took lessons at the Oberlin Conservatory where he studied with Mark Edwards, Michael Lynn & David Breitman. It was then that he also began to take composition seriously and in 2019, he composed an opera "The Spectres" which premiered at Oberlin’s annual Baroque Performance Institute.

At 16, he moved to Montréal, Canada and enrolled at McGill University where he undertook studies in harpsichord under the tutelage of Hank Knox and piano with Ilya Poletaev. While in Montréal, he founded the early music group Ensemble Bonaventure which went on to perform 3 years worth of successful concerts. Their inaugural performance was a fully staged production of Purcell's Dido & Æneas, which received an encouraging critique in Revue L'Opéra and led to an invitation to perform Rousseau's Le Devin du Village at the 2023 edition of the Festival Montréal Baroque.

While in his last year of studies at McGill, Plansker became increasingly interested in orchestral conducting at the encouragement of his mentors Elizaveta Miller and Dorian Bandy. He began to organize larger concerts with larger orchestras and choirs, performing Beethoven's Symphonies 5 & 7, Bizet's Jeux d'Enfants, excerpts from Mozart's Idomeneo & the North American Premiere of Thomas Linley Jr's Music for the Tempest with soprano Sophie Naubert. In 2024, he served as an assistant conductor for an Opéra McGill production of Massenet's Cendrillon under Stephen Hargreaves.

In August 2024, Plansker moved to the Netherlands to pursue a master’s degree in pianoforte performance with Olga Pashchenko at the Conservatorium van Amsterdam. Inspired by the passion for Romantic performance practice there, he joined forces with his friends and colleagues to found Orchestra Lagrandt, a period performance orchestra with a specialization in 19th and early 20th-century repertoire. They gave their first concert in March 2025 with the "Great" C major Symphony of Franz Schubert alongside a string serenade composed and conducted by Plansker. During their '25-'26 season, they have performed Tchaikovsky's Third Symphony (November), J. S. Bach's Johannes Passion in a late Romantic-style arrangement by Plansker (March), as well as a program of early 20th-century chamber orchestra repertoire (May). The group was recently featured as a winner of Early Music Vancouver's prestigious Emerging Artist Competition.

After receiving childhood training in the Cecchetti method of ballet from his mother, Plansker developed an interest in the intersection of ballet and music. Since 2022, he has become a sought after accompanist, collaborating with names like Raymond Lukens, Diane van Schoor, Jean-Yves Esquerre, Anita Young, Dinna Bjørn, Eric Viudès, Diana Byer, and Grigori Tchitcherine, among many others. Between 2024 and 2026, he was a staff accompanist at The European School of Ballet and Het Nationale Balletacademie, and he has been an accompanist at for the Cecchetti Council of America's International Summer School since 2022. In the summer of 2024, he was invited as a guest accompanist for the Cecchetti International Classical Ballet Competition in Holland, USA.

As a composer, Plansker considers himself a proponent of fin de siècle tastes. He has composed in an extensive range of genres and premiered his works across North America and Europe, including with frequent collaborators, Alice Boissinot Guastavino (soprano), Erik Schroeder (violinist/composer), Vincent Canciello (flutist/composer), Camille Poirier-Lachance (violinist), and Alyssa Campbell (violinist).