SATURDAY night 40-odd students, faculty and alumni of Yale sang of God, war, the Russian land, and love. The jingoism of some of the texts seemed a little ill-timed, but this apparently bothered the audience of Harvard academics not at all. The group's contagious enthusiasm and thoroughly convincing musicality brought the audience cheering and stamping to its feet.

The Yale Russian Chorus is overwhelming. Within the first two hymns on the program they showed themselves as capable of a perfectly controlled triple piano as a gigantic, masculine fortissimo. As choruses go they are not large, but when they open up they sound like a stereo system turned to 11 1/2 on a scale of 12.

The group's vocal range is as wide and impressive as that of their dynamics. The first tenors more than once soared into the ethereal region two octaves above middle C, while the second basses were continually plumbing the depths and at one point actually reached the third B-flat below middle C.

Solos were generously distributed and inevitably some voices proved less fortunate standing alone than others. One baritone in particular had egregious difficulties with intonation, singing either sharp or totally out of tune. Nonetheless he more than redeemed himself in Akh, Ty Step Shirokaja, that emotionally charged and typically Russian hymn to the Volga River. By and large the soloists were excellent and served less to highlight particular individuals than to underscore the power and expertise of the group as a whole.

Under the exuberant direction of Denis Mickiewicz the group sang as one like a great human organ with vocal chords in place of pipes. Their repertoire is small but polished. Everything is done from memory and it was obvious from the performance that the chorus knows each selection inside and out.

SUCH mastery of material allows the conductor a great deal of flexibility, and Mickiewicz capitalized fully on the chance. His conducting was demonstrative, fluid, and expressive, moving in phrases instead of measures. His lines were lovingly shaped, sometimes elegantly, sometimes extravagantly. Mickiewicz is a master of that peculiarly Slavic kind of rubato whose sentiment hovers between joy and sorrow and has a gradual rocket accelerando that makes the Rossini crescendo dull by comparison.

The Yale Russian Chorus is not without its faults. It has a tendency to get carried away with its own enthusiasm and power. In an immediate sense this leads to forcing and a regular tendency to go sharp, spoiling an otherwise acute sense of balance and intonation. By not conserving its strength, the chorus in the long run wears itself out.

But in terms of Russian song the question of restraint is probably irrelevant. There is nothing diminutive about this music. Everything is done in broad strokes and grand gestures. The syllables are rich and mouth-filling, the chords are full, and the passions are great, and as long as somewhere in the world these exist, there is still reason to hope.