portamento explained
A vocal or instrumental technique of sliding smoothly from one pitch to another, passing through all intermediate pitches
In Depth
Portamento (from the Italian portare, to carry) creates a continuous glide between two notes. On string instruments, the finger slides along the string; in singing, the voice sweeps between pitches. Portamento was a standard expressive device in Romantic performance practice, but 20th-century taste turned against it as sentimental. Historical recordings from the early 1900s reveal a far more lavish use of portamento than modern performers typically employ, suggesting that our aesthetic norms have shifted significantly.
Early recordings of violinists like Fritz Kreisler and Jascha Heifetz contain so much portamento that modern listeners sometimes mistake it for poor intonation.