Other forms: philharmonics
The word philharmonic describes a group or organization that's dedicated to music. It's especially common as part of the name of large music ensembles like the New York Philharmonic or the Vienna Philharmonic Orchestra.
Sometimes this word is used for orchestral music, so you could describe a symphony as a philharmonic piece. You're much more likely to find it in the names of symphony orchestras, though, from the Berlin Philharmonic Orchestra to the Los Angeles Philharmonic. The word was first used in English around 1913, from the Italian filarmonico, "loving harmony," and its Greek roots philos, "loving," and harmonika, "harmony or music."