1. dialog (with a tree) à Katerina Xirou2. breath'n beat à Philippe Leroux3. Lib ...4. 100 phonems à Bjork5. Singing tubes à Demetrio Stratos Práxis 4 saxes is a cycle of short pieces for saxophone quartet commissioned by French Radio and written for the Habanera saxophone quartet.My intention was to preserve each piece's autonomy in order to explore music materials and instrumental techniques specific to each.Dialog (with a tree) originated from "Neratzoula", a traditional greek music's classic; it's a short song in dialogue form about a walker announcing the coming of the winter to a tree.The tittle reflects the form of the song as well as my own relation to an aural tradition whose elements undertake here the role of "memory activators" rather than local idiom transmitters.The melody, used in an extremely expanded form, constitues the harmonic and melodic material of the piece; for the latter I have chosen a diffracted writing on the four saxophones including isolated pitches or melodic cells ornamented sometimes in the Epirotic clarinet style.Breath 'n Beat is mainly a rythmic piece based on a constant pulse similar to that of rock, blues or word music.The sound material uses mainly short and percussive sounds, and saxophone sounds combined to vocal sounds projected into the instrument.This piece has helped me to break through some thresholds of what is considered contemporay music writing by the use of steady beat for almost the whole piece and the deliberate simplicity of rythmic motifs and metrical subdivision.Lib is a piece which would be seen as the base for an improvisation regardless of its organisation.It is based on a timbre elaboration ranging from the instrumental timbre to the "acoustic hybrid", the latter being the singing voice projected into the instrument and altered by it.An instrumental glissando texture evolves in dense tremolos then in a noisy texture by adding the voices to end in glissandi again on the high register.While the choice of timbres is the one element which should be followed by the performers, the ambitus, the register and the durations could vary in each performance.100 Phonemes is caracterised by the abolition of pitch and the exclusive use of noisy-unvoiced phonemes amplified by the saxophone. The phonemes are organised in three different registers percieved as hight - medium - low, their time-variable amplitudes pointing to the breath envelope expressed by the relation crescendo - breath in / decrecsendo - breath out.A whispered text in different speeds has been used on certain instances for its acoustic properties in relation to phonemes articulation; the text can be freely chosen by the performers, its textual message having no importance.Singing Tubes has to do with the voice transformed by the saxophone, a research accompaning my work since a long period. The exploration of limits between voice and instrument practices by one performer pushed me to discover a technique wich I call "artificial vocal bisbigliando" or "hybrid vocal bisbigliando", used for the first time here : a microtonal variation of the singing voice projected into the saxophone due to some special fingering changes. This technique in full evolution, by offering particularly new and reach timbres, claims for an attentive exploration of the relation register - fingering - voiced phoneme - position of the voice througth writing and experimentation.