If you are unfamiliar with Finnish music -- as I was when I first discovered Varttina -- it can be a fascinating enigma. Just when you think you have it pinned down, the music will give an unexpected wriggle and suddenly sound quite different. At times it seems to tap into a primal, shamanistic tradition, or the great heritage of oral sagas; at the next moment, it skips off in a rollicking and utterly normal polka. Both Scandinavian and Slavic influences can be heard, along with unexpected overtones of Celtic, klezmer and Middle Eastern music.

Varttina (the name means "spindle" in Finnish) was for several years a major force for traditional music in Finland. At the time of this recording, the mostly-female ensemble numbered 11 members. In addition to five singers, the group also featured kantele (a folk instrument similar to the zither), accordion, bass, fiddle, guitar, mandola, percussion and wind instruments. Oi Dai was their third recording and the earliest one to be released in the United States. It was the breakthrough album which established Varttina's reputation in Finland, where it became the biggest-selling folk album in 20 years.

Some of the songs are jolly and rowdy -- the sort of thing someone might strike up for a sing-along on a hayride. Others are chantlike with many quick syllables, performed either with accompaniment or in the group's trademark a cappella settings. There are two fine instrumental tracks reflecting the major cultural influences on Finnish music: "Kamaritski" sounds very Scandinavian, with a cheerfully lopsided melody, and "Tantsukolena" has a strongly Russian sound.

Two tracks deserve special mention. The first is "Viikon Vaivanen," a song taken from a charm for banishing disease. The sinuous melody is first performed slowly a cappella; then it swings into a faster rendition supported by an asymmetrical pulse from the bass and crisp taps on the bongos. More voices, accordion, fiddle, and wind instruments are added in various combinations. Amazingly enough, much of the performance is in unison or very simple harmonies; the interest comes from the mixing and combining of various tone colors.

The second standout is the title track, "Oi Dai." The singers make effective use of harmony on the repeated phrases. Although the song is slow, it is not allowed to drag. The vocals ride with deceptive smoothness over a constantly shifting and changing instrumental bed. Sharp and urgent percussion drives the whole ensemble forward. The overall effect is hypnotic.

A slow and meditative song, "Yks on Huoli," closes the album.

One of the pleasures of listening to Varttina is the sound of the Finnish language. The group has a strong vocal section with excellent diction. Even if you do not speak a word of Finnish (I certainly don't), it is possible to pick out the intricate alliteration and rhymes. For those who like to know what they're hearing, the liner notes provide both translations of the songs and transcriptions of the Finnish lyrics.

Varttina's next recording, Seleniko, probably marked their high point as a traditional band. Compared to the later recording, Oi Dai sounds a bit rougher around the edges. The performances are slightly less polished, and the recording techniques are not as slick. However, it is a worthy companion to the later album. After Seleniko, Varttina moved away from traditional Finnish music. Their subsequent releases have focused on original compositions and, I confess, have not succeeded in capturing me. Luckily, through these early albums it is still possible to enjoy their days as a fine traditional band.