The .part3.rar extension indicates that the original data (likely a large folder of FLAC or WAV audio files, or a high-definition video of a concert) was too large for a single transfer.
A prestigious box set recorded live at the Philharmonie Berlin. This set is famous for its "Direct-to-Disc" vinyl releases and high-resolution digital audio (24-bit/192kHz). Sibelius_Rattle.part3.rar
Often included are works like Finlandia , The Oceanides , or Tapiola . Sibelius_Rattle.part3.rar
Scans of the liner notes providing historical context on the performances. Sibelius_Rattle.part3.rar
Based on the filename , this file is the third segment of a split RAR archive likely containing high-quality recordings of Jean Sibelius's symphonies conducted by Sir Simon Rattle . Context of the Recording