Only for the most devoted listeners: a slender autobiography by pop singer/composer Sedaka--who devotes most of the space here to watching Ms hits rise or fall on the charts. Born in Brooklyn to mixed-Jewish parents (Sephardic, Ashkenazi), little Neil grew up as a scrawny sissy: ""The destruction of my ego was well underway. I was a troubled child headed for a tragic, empty life."" But a schoolteacher spotted his musical talent, classical piano training followed--and early-'50s pop songwriting too: ""Suddenly I was a high school celebrity,"" a teenager-writer with songs on the charts. (First biggie: ""Stupid Cupid"" by Connie Francis.) Success as a singer came only slightly less quickly--not really peaking till ""Breaking Up Is Hard to Do,"" with its ""obbligato line that had come to me in the middle of the night and was destined to become one of the most famous of all time: Down-Doo-Be-Doo-Down-Down, Comma, Comma."" But after superstardom (1961-1963) came ten years of relative failure: ""I was able to write hit songs for others, but Neil Sedaka the performer was totally washed up."" And only after finding a new lyricist, help from Elton John, and marijuana (""a great creative tool"") was there a comeback at last: ""Laughter in the Rain."" Sedaka touches briefly on his family here too: wife and kids; an overbearing mother who held onto the purse-strings for years. And there are tiny glimpses of show-biz colleagues--Bette Midler, Maurice Gibb, the Carpenters. But the problems (with Elton John, obesity, Mother) are superficially skirted over--with the breathless emphasis always on Getting-Another-Big-Hit. In all: strictly fan-club material.