Compared to the colourful Symphony No. 3, the Fourth appears almost as its opposite. The unique aura of the composition is determined by the line-up (Mycielski removed percussion instruments from the orchestra) as well as the division of the material, for example of the violins into twelve groups in the introduction. In his commentary to the Poznań performance of Symphony No. 4, the composer explained the principles behind its form as follows: “The work, performed without intervals dividing it into movements, contains clearly fast and slow, meditative sections” (programme booklet of the 1976 Poznań Music Spring festival, p. 9), adding a few years later that the symphony is a “kind of arranged improvisation for orchestra” (programme booklet of the 1980 Warsaw Autumn International Festival of Contemporary Music, p. 183). 

The work consists of contrasted fragments like in Mycielski’s earlier compositions (Five Preludes for string quartet and piano, Symphony No. 3). Mycielski juxtaposes sections that are extremely subtle, as if spiritual – unfolding almost beyond time and surprisingly archaic despite the composer’s use of an individual twelve-note technique, sections often entrusted to the string quintet with added colour being provided by the piano and the harp – with motoric, dynamic sections that are more intense from the textural perspective, emphasising the sound of the wind instruments.

After the Poznań performance Ludwik Erhardt, Mycielski’s colleague from Ruch Muzyczny, wrote:

Zygmunt Mycielski’s Symphony No. 4 [...] is music that is very beautiful and perhaps too concise because of that.  The composer’s [...] commentary suggests that he treats the name ‘symphony’ rather freely, simply referring it to a piece for symphony orchestra. Therefore, the feeling of dissatisfaction I experienced when the last note of this music died away was not due to the expectation of an elaborate, cyclic symphonic form, but to the regret that the composer, introducing the listeners to the beautiful world of his sonic ideas, allows them to stay in it for such a short time. This music, woven from lyrical reveries, subtle colours and gentle lines, has [...] a strictly defined structure, based on an individual variety of the serial technique. It is a variety seeking to eliminate the greatest sin of serial techniques so far – monotony. It consists in constructing incomplete series and meticulously omitting, in the course of the music, notes not taken in account in these series – in order for them to be introduced unexpectedly and to sound like a fresh element, something new, an unexpected modulation to a new key. [...] by submitting himself to the strict discipline of the system he established, Mycielski achieved such a condensation of form of which the long-winded and messy contemporary music has long since disaccustomed its listeners ([Ludwik Erhardt], “O koncertach XVII ‘Poznańskiej Wiosny Muzycznej’ piszą: Ludwik Erhardt, Andrzej Chłopecki, Tadeusz Kaczyński, Krzysztof Meyer. Inauguracja”, Ruch Muzyczny 1976 no. 11, p. 14).