A singing voice synthesizing apparatus is provided, which enables achievement of a natural sounding synthesized singing voice with a good level of comprehensibility. A phoneme database stores a plurality of voice fragment data formed of voice fragments each being a single phoneme or a phoneme chain of at least two concatenated phonemes, each of the plurality of voice fragment data comprising data of a deterministic component and data of a stochastic component. A readout device that reads out from the phoneme database the voice fragment data corresponding to inputted lyrics. A duration time adjusting device adjusts time duration of the read-out voice fragment data so as to match a desired tempo and manner of singing. An adjusting device adjusts the deterministic component and the stochastic component of the read-out voice fragment so as to match a desired pitch. A synthesizing device synthesizes a singing sound by sequentially concatenating the voice fragment data that have been adjusted by the duration time adjusting device and the adjusting device.