Wagner began writing the opera Parsifal in 1857 but didn't complete it until 1882. It's first performance was given at Bayreuth just 4 months before his death. It is loosely based on a 13th-century epic poem of King Arthur and his quest for the Holy Grail.

Randall Malmstrom's beautiful arrangement of the music for 8-part Trombone Ensemble is noble and spiritual.

This 4-minute excerpt contains much of the Introduction or Vorspiel and is appropriate for advanced performers.

The instrumentation is for: 2 alto trombones, 4 tenor trombones, 2 bass trombones

Sergei Rachmaninoff's Prelude Op. 3, No. 2 is one of the composer's most famous compositions and is also known as The Bells of Moscow since the introduction seems to reproduce the Kremlin's most solemn carillon chimes. (Wikipedia).

This fantastic arrangement in C minor (the original is in C#) by Kevin Dombrowski for 8-part Trombone Ensemble certainly retains the immense gravity and solemnity of the piano version if not more, with the rich and dramatic sounds of the trombones.

The 4-minute arrangement is appropriate for advanced performers.