The title of pianist Tord Gustavsen's sixth offering for ECM is, like his compositions, elusive on the surface but imparting multiple shades of meaning.

His first three albums with the label showcased a trio; his last three the expanded setting of a quartet.

Gustavsen's pianism is distinct and was developed over time while backing vocalists.

The subtlety and lyricism from that time are embedded in his compositional DNA.

His music as a bandleader has moved ever outward from a still -- not static -- center.

This was especially prevalent on the trio recordings, where an intentional emphasis of restraint was placed on timbre, texture, and space (and can be heard on the bookend trio pieces here, "Right There" and "The Prodigal Song").

Over the quartet albums, his work has embraced a wider palette of colors and dynamics with a considerably expanded harmonic field.

With saxophonist Tore Brunborg, bassist Mats Eilertsen, and drummer Jarle Vespestad, Gustavsen pushes at the boundaries of the circle and expands its reach.

The traditional Norwegian hymn, "Eg Veit I Himmerik Ei Borg," showcases elegant chord voicings balanced by a turbulent, rhythmic undercurrent led by Vespestad's simmering drums, and woody dynamic support from Eilertsen that adds tension and dynamic.

Brunborg's solo moves to the edges, nearly free of melodic constraints as Gustavsen's changes become more percussive to accommodate him.

"Staying There" is an excellent showcase for Brunborg on a nearly funky blues groove.

"The Gift" finds his rumbling tenor utterance in the tune's head, deep, warm, and soulful above a spacious, circular piano vamp and a rhythm section whose playing alternates between procession and shuffle.

"Devotion" features lovely arco playing from Eilertsen in a rubato tone poem; its melody is based on Christian sacred music.

The elliptical group playing at its center is especially appealing and connected.

"The Embrace" is a canny modern jazz meld of gospel themes and soul music.

On the midtempo "Glow," Gustavsen's vulnerability shines through as Brunborg answers his lines with emotive assent and encouragement.

On Extended Circle, the pianist's roots remain contemplative, but the maturity of the communication among these players provides a more fluid and physical sense of motion, revealing a multi-faceted approach to both playing his tunes and improvising.