Estonia is a young nation, but it has influential neighbours. One theme at this year’s Estonian Music Days festival was the relationship between the contemporary music scenes in Estonia and Poland. The Warsaw Autumn Festival changed the musical landscape in Poland from the 1950s onwards, but its effects were also felt further afield. In the Soviet era, some Estonian composers were permitted to attend the festival, one of the very few opportunities for foreign travel, and an important window on musical developments abroad. This evening’s concert brought the story up to date, demonstrating continued links between the two countries. The young Polish group Ansambel Sepia presented a two-part programme, the first part dedicated to new music from Estonia, the second to works from Poland. Many connections were evident, but so too were the distinct identities of the two musical cultures.

Ansambel Sepia is based in Poznań and is made up of students and recent graduates of the city’s music academy. Their standards are high, but the sheer enthusiasm of the group is just as important to the success of the project. The ensemble tours widely, divising programmes that link contemporary Polish music with that of other nations. This evenings programme, named “Zooming Estonia” follows a similar events focussing on Ireland, Luxembourg and Korea. The group also performed an Estonian-themed even in Poland last year, with only one work overlapping with the programme of this Tallinn event.

The five Estonian works in the first half date from 2007 to 2015, all for chamber ensemble, various combinations of strings, woodwind, piano, trombone and percussion. There was only one première here, Aither by Age Veeroos, but that proved a highlight. Most of this piece is made up of breathy, unpitched sounds, breathing into the trombone, a sheet of paper brushed across the strings of the piano. But from this background definite pitches gradually emerge, as if reluctant to come into the foreground. The whole process is very gentle, and teasingly ambiguous, but describes a clear arc, with the notes eventually receding into the unpitched sounds and the work ending with gentle brush of a bowed cymbal.

Thule Variations, by Tõnu Kõrvits, stood out in this programme, as did his silent songs in the previous day’s orchestral concert, for his overt use of folk music elements and his post-minimalist language. Estonian new music tends to be expansive and gradual, but it rarely has specific links with repetition-based minimalism, and tonal allusions are rare. But Kõrvits is the exception, as this work for string quartet demonstrated. Yet there is nothing neoclassical about this music. Short melodic fragments appear, each with a specific modal identity, but are refracted through heterophonic textures and rhythmic patterns in the four instruments that are never quite in agreement. Despite its general consonance, the resulting music is curiously unsettling, always unstable but for reasons that remain unclear.

Comparison between the two halves of the concert seemed to validate many of the stereotypes about the musical identities of the two nations. Where the Estonian music was generally slow and based on brief thematic ideas, the works by Polish composers were generally faster, but much more focused on the timbre and sound quality as the basic musical material. If Lutosławski’s Grave, Metamophoses for cello and piano proved an exception to that rule, it was only for the stately elegance of his melodic material, which was, in any case, elaborated with a keen ear for the timbral relations between the two instruments.

As with the Estonian works, most of the Polish music here was written in the last seven years. The first piece, Miniatures sonoristiques for solo trombone, by Ewa Fabiańska-Jelińska, was particularly inventive in its use of extended techniques – tapping the bell, growling while playing, buzzing into the detached mouthpiece. But, unlike many such works, the piece was more than just “experimental”, describing a clear and rounded form across its seven miniature movements.

In his Trio for violin, cello and piano, Michał Ossowski seemed to be imitating, by acoustical means, the effect of tape delay, with each of the declamatory sounds immediately repeated several times in diminuendo. The venue for the concert, the Hall of the Tallinn Secondary Science School, is a tall, marble-lined affair, too resonant for most of the music, but the ideal complement to Ossowski’s echo effects. Rafał Zapata and Artur Kroschel, the co-directors of the ensemble each contributed a work, both for six players (but five instruments in the former case, as Zapata has two performers at the piano, one at the keyboard and one under the lid). Kroschel’s Fracture proved the more interesting of the two, the title apt for music of brittle harmonies and unstable textures, always seeming in imminent danger of collapse.

To conclude, a classic of the Polish avant-garde, Swinging Music by Kazimierz Serocki, dating from 1970. The piece is based on a continuous and unchanging pulse, and crotchet followed by two swung quavers. But this is passed around the ensemble – clarinet, trombone, double bass, piano – each using radical extended performing techniques, the unchanging rhythm holding the music together in spite of the radically heterogeneous textures. Unintentional comedy is always a risk with extended techniques (the Fabiańska-Jelińska raised a few unwelcome smirks from the audience), but Serocki counters this by making every slapstick effect deliberately comic. It’s a great closing number, and a convincing demonstration of the fact the radical new music doesn’t always have to be presented with a straight face.