I know it's maybe not the best quality recording (our recent British Trombone Society recording on CD is far better - buy it on the British Trombone Society website), but this was Trombonanza's performance in 2009:
http://www.youtube.com/watch?v=Oq5TUL3tPUo
Enrique Crespo's Bruckner Etüde für das tiefe Blech exists in two main variants, viz. quartet and sextet. The quartet version is significantly more difficult to perform, as it condenses material for six voices into four. The quartet version is available for four tubas or four trombones, while the sextet version is available for six tubas or six trombones, as well as two horns, three trombones and tuba. We've always done it with four tenor trombones, one bass trombone and one contrabass trombone, exactly as the New Trombone Collective.
If you're interested in original music for trombones by Anton Bruckner, check out Zwei Aequale für Drei Posaunen. I recently had the pleasure of performing these along with Afferentur Regi and Ecce Sacerdos Magnus on a set of German trombones and it was a really wonderful experience. The Aequale and Afferentur Regi are also, remarkably, scored for the alto trombone. I wrote the programme note for the concert, which may interest you:
QuoteIn the 18th century, equal or equale became established as a generic term for short, chordal pieces for trombone quartet. Old church music regulations from Linz in the province of Upper Austria, where Bruckner lived and worked in his early years, show that such pieces were used at funeral services in Austria. The performance of such pieces from towers on All Souls' Day and on the previous evening is associated with the funeral service, thereby underscoring the long-held ecclesiastical association of the trombone with funeral rites.
Notable examples of the genre are the Three Equale for four trombones of Ludwig van Beethoven (Drei Equales, WoO 30), written for performance in Linz Cathedral on All Souls' Day, 2 November 1812. Two of them were later performed, with the addition by Ignaz von Seyfried of words from the Miserere, at Beethoven's own funeral in 1827, and also as instrumental pieces at the funeral of William Gladstone in Westminster Abbey in 1898. In 1844, the little-known composer Wenzel Lambel (17881861) of Linz published ten equali for three or four trombones.
In January 1847, Bruckner's mother informed him of the passing of his aunt and godmother, Rosalie Mayrhofer, whose death apparently stimulated the composition of the Aequale for three trombones. In fact only the piece now identified as Aequal No. 1 (WAB 114) can be precisely dated, though as both works exhibit identical style, it seems reasonable to assume that they were written at the same time. The manuscripts consist of parts only without full scores and while it would appear that Bruckner was intending to write a series of such pieces, only the first is complete, the second consisting only of alto and tenor trombone parts in Bruckner's hand. The bass trombone part for Aequal No. 2 (WAB 149) has to be reconstructed for any performing edition and that used tonight has been specially prepared by Edward Solomon. These two short and solemn works are remarkable for the fact that the composer uses the alto trombone, an instrument that was rarely used by the mid-nineteenth century.
Apparently, Bruckner's Aequale and other similar music was performed at the outer gate to the abbey of St. Florian, near Linz, where the dead were placed until the priest could undertake the consecration. Although intended as funeral music, it is possible that Bruckner's Aequale express hope and comfort rather than grief. This is supported by the composer's harmonic choices. While both pieces are nominally in C minor, large sections of them are in the major mode and almost all phrase cadences end on major chords, bringing a serene, reverent quality to both works.
In fact I did more mistakes 
This is not a Bruckner composition, and I also forgot the link 