This CD is a homage to the memory of Antonio Mereu, a great a tenore singer from Oliena (a small village in the Barbagia region, 20Km from Nuoro), who dead before his time on March 2, 2000.
The eight tracks of the CD are performed by the “Raimundo Congia” a tenore quartet, that was founded in 1997 by Giovanni Porcu (boghe – i.e. the solo voice), Salvatore Boe (Mesa Oghe – the highest pitched voice), Pietro Carrus (contra – the central guttural voice of the choir) and Antonio Mereu (bassu – i.e. guttural bass). The denomination of the group derives from the name of a poet from Oliena (Raimondo Congiu) who lived in the 18-19th centuries. (...)
(in the booklet, inter alia) Sebastiano Pilosu extends the description of the features of the Oliena’s a tenore traju. He basically says that for an external auditor the Oliena’s style can sound similar to the other of the neighbouring village (Orgosolo). But for the Oliena’s inhabitants and for the expert listeners there are some peculiar elements that are of its own characteristic and cannot be found anywhere else. For instance he observes the nuances in the timbre of the guttural voice that is delivered with a half-open mouth. Another peculiarity of su traju is the oscillation between the distance of a fourth and a fifth made by sa contra in the respect to su bassu, a very strong distinctive element with regard to the the next villages where the interval between contra and bassu is fifth and sixth.

from cd: Tenores, Suoni di un'isola,ed. by Marco Lutzu, Livestudio 2003
http://www.livestudio.it/it/scheda.php?id=18

The a tenore song is a multipart singing in four parts, typical of the middle-north of Sardinia, where each part has to be sung by one single male singer (cantore). As each part can not absolutely be doubled, the group of tenores has to be composed of four people.
The formal structure of the a tenore song can be essentially defined as a canto ad accordo, that is a melodic line, performed by a soloist, sa 'oghe (the voice), which is accompanied by chords made by the other three cantori (singers).
The ethnomusicologist Pietro Sassu has been the first to consider the group (gruppo) which sings a tenore not as a choir but as an "integration among four soloists" [Sassu 1982], because, despite their often sought homogeneity and fusion, each element approaches his part in a personal way, and with a certain freedom of variation: the purpose is the fusion of the voices, not the anonymous overlapping of sounds. To define the group of the four singers, of their way of singing, the term tenore (in the singular form to indicate the four cantori) or tenores (the components) is certainly the most wide-spread, even if in some villages they use terms like su cuntrattu (in Seneghe), su cussertu or su cuncordu (in Fonni). According to the villages, then, these terms sometimes indicate the group of the four singers, sometimes only the choir of the three elements who accompany the soloist.