Despite Frank Zappa’s infamous distaste for narcotics he was, for many, a gateway drug into the seamy underbelly of avant garde classical music. Championed and commissioned by Pierre Boulez, he often quoted passages of Stravinsky’s ballets and he frequently used the splice techniques of Pierre Schaeffer. But his most lasting classical debt was always to Edgard Varèse. Frank even called Varèse on the phone, when he was 16, to express his admiration. I mention all this is all by way of explanation of the pairing of seemingly disparate composers by Ensemble Musikfabrik. It makes perfect sense to me.

The opening work Revised Music for Guitar and Low-Budget Orchestra reveals the conflict at the centre of Zappa’s reputation, an awkward conjoinment of the ‘statistical density’ of eccentric composition and the loose jam-session feel of a live rock band. It was followed by RDNZL, another odd choice which at its best wends intricate and wayward paths to dead-ends and musical trapdoors. Lemme Take You To The Beach was pure frivolousness, not much more than a catchy tune, and therefore seemingly out of place at a festival such as Musikfest Berlin.

The musicians disappeared and all of a sudden the entire stage span around on its axis to reveal an even bigger set up of percussion for the Varèse section of the concert. An ejaculation of applause erupted for the stage-setting itself. The music couldn’t have been in greater contrast. Solemn, ritualistic and seemingly made of sheer granite, Ecuatorial towered in magnificence and mystery. This was proper music. Robust, sincere, tough.

Speaker Michael Leibundgut sang, intoned and recited from Francísco Ximènez’s telling of the Mayan creation myth accompanied by fiendishly precise brass, an intergalactic pair of ondes Martenots, along with a battery of percussion: a piercing blast of imagined prehistory, performed with requisite grandeur.

The real granddaddy of the concert was the reverend Ionisation for 13 percussionists. After all, this was the one that got the 16-year old Zappa so excited way back in 1956. Conducted by Carl Rosman with amazing exactitude and menace, this was by far the freshest I have ever heard.

Varèse being a pioneer of electronic music we had to have a bit of his electronic output. Playback of prerecorded Poèm èlectronique engendered a few smirks in the audience as some of the sounds have not aged well, but it is always worth a listen. The stage then span back to the Zappa position, this time while the ensemble ripped through all three versions of Frank’s The Black Page (named after its tightly crammed score). The first version is Zappa’s homage to Varèse’s pure use of percussion, the second superimposes a dizzying melody, and the third gloops a disco vamp on top.

With drummer Dirk Rothbrust centre stage, the rest of the concert took off like a rocket. Playing Echinda’s Arf (Of You) and segueing into Don’t You Ever Wash That Thing? was an inspired decision, leading to anarchic improvisations and near-chaos worthy of the original Mothers of Invention. Stunning brilliance. A glorious encore of Peaches en Regalia gave most of the audience what they probably came for.

Zappa’s orchestral and ensemble music may put him light years beyond his contemporaries in the rock and pop scene of the 60s, 70s, but when placed in the context of the real experimental masters, his scores can pale, unless the band are good enough to play the right notes when they need to and the wrong notes when they want to.