The Comedian Harmonists was an internationally famous, all-male German close harmony ensemble (5 singers plus pianist) that operated between 1927 and 1934. They were one of the most successful 20th century musical groups in Europe before World War II and were noted for using their voices to imitate musical instruments. The Comedian Harmonists were founded in Berlin-Friedenau in the flat of Harry Frommermann (Stubenrauchstraße 47). Today a commemorative plaque marks the spot.
From the perspective of the early years of the twenty-first century, now that numerous tribute groups have established themselves to recreate something of the sound of the Comedian Harmonists, it is arguable that the extraordinary degree of sympathy which the members of the original group achieved is unlikely to be matched again. The hallmark was the unusual extent to which the members were able, whilst having different vocal qualities one from another, to blend very accurately and subtly so that the individual singers could appear and disappear back into the vocal texture with almost effortless skill. The obvious sincerity and affection with which they approached their music-making helped to make the results unusually attractive.
The choice of repertoire was wide, ranging from folksong and classical numbers (usually arranged by the energetic and sensitive Frommermann) to the attractive and witty popular songs of the day by such writers as Peter Igelhoff, Werner Heymann and Paul Abraham.
As to the members of the group themselves: once the form which brought a lasting reputation had been established, it is hard to see how the group could have done without any of them. Supported by Bootz, the boy from Stettin who had trained as a concert pianist, each member had something unique to contribute. Frommermann himself was a capable tenor, with a mellifluous speaking voice which he used very effectively and confidentially from time to time; he also supplied most of the bizarre vocal interjections (and stage antics) that decorated the more lively songs. Robert Biberti, Frommermann's first recruit, had an extremely flexible and, from time to time comically communicative, dark ("black") bass voice which the group frequently used in solo work beneath a flowing accompaniment by the others. The baritone Roman Cycowski's operatically powerful and melodically pleasing timbre provided essentially the heart of the Comedian Harmonists' unique sound. Erich Collin, who joined the group in 1929 as a replacement for the original second tenor Walter Nüssbaum, besides acting as the secretary of the group (he spoke seven languages) had a musicianship which allowed him to secure the most awkward and crucial harmonic moments with complete accuracy, whilst the silver-voiced Ari Leschnikoff quickly became a household name for his ability to sing a top part out of the reach of most comparable tenors: he was said to be able to sing a top F on the treble stave without using any falsetto.
Source:
http://en.wikipedia.org/wiki/Comedian_Harmonists