On their fifth album, Swedish vibraphonist Mattias Stahl joins the Portuguese RED Trio as a guest. He's the latest in a sequence which includes alliances with saxophonist John Butcher and trumpeter Nate Wooley on disc, and reedman Ken Vandermark in performance. The product, North And The Red Stream,  comprises three collective improvisations recorded at the VDU Jazz  Festival in the Lithuanian city of Kaunas in 2013. Each arises from an  impromptu give and take, negotiated on the fly, as the principals  continue to exercise the democratic ethos which has served them so well  to date. 
 Unsurprisingly the integration of the Swede serves to  emphasize the percussive aspect of the outfit. As always with such  freeform activity, well-balanced tonal placement is key, and the four  prove accomplished practitioners. Perhaps it's the similarity between  the vibes and prepared piano that results in pianist Rodrigo Pinheiro  spending more time on the keys rather than under the bonnet. Gabriel  Ferrandini reaffirms his place among the cream of European drummers  (though he was actually born in the US) eliciting a clattering momentum  formed by bursts from different parts of his kit. He displays a  particular talent for atmospheric sound sculpture derived from cymbal  scrapes and squeals. 
Bassist Hernani Faustino adds a surefooted  undertow, whether through a throbbing pizzicato or abrasive arco swipes.  Ståhl draws a stunning range of expression from an instrument that can  seem one dimensional in lesser hands. He accentuates the vibes metallic  nature on "North" by reducing the sustain to almost zero, while  elsewhere he takes the opposite tack by extending the sustain so that  they resemble a synth or electric piano with a wah wah quality. His  reiterated motifs and ringing glissandos provide a structural element  which blends well with the resonance emanating from Pinheiro's dampened  piano strings. 
Pinheiro shows himself at his most demonstrative  at the start of "North," working in squalls of notes. He moves through  swelling crescendos, angular comping and insistent tremolos. Several  passages of artfully combined textures derived from hammered piano,  cymbals and rattling vibes, such as that around the 10-minute mark in  the same piece, show recognition of a fertile gambit. Masterful  interplay, notable for Faustino's knotty flurries, builds tension on  "Stream" before winding down to first a swirling stasis, then silence.  While the set explores a more restricted sound world with less  contrasting voices than previous collaborations, it nonetheless  possesses ample charms and will appeal to anyone who enjoys the  klangfarbenmelodie of tuned percussion.