Sam Riversof d seriesSam Rivers, one of jazz's most i m lt;ig i not i ve i n s I ru men ta I is Is. entertained a small crowd at the Neiv Varsity Theatre last Wed-nesday night. The show was the first in a series that premises to bring jazz to Palo Alto every week. 4Hivers. leading a trio, played two hour-long improvisations as he played four different instruments and occasionally sang wordlessly with his hand. Rivers opened on tenor sax, his best-known instrument and he showed his ability to play at almost any dynamic levelr wwith a growling tone halfway between speech and conventional playing.A highlight was Rivers' sweet unaccompanied solo on the soprano sax. joined later by his fine local bassist. Chris An burger. On flute, Rivers got what sounded like a primitive three-part harmony by humming and playing simultaneously.And surprisingly, the instrumentalist played two strong piano solos that showed the influence of Rivers’ one-time Daily photo by Hilary Han band leader, Ceci I Taylor.