Q: I'm now studying Larsson Concertino and I wanted to ask you something. In the second movement I like to use vibrato on some notes, and I've noticed that when I do it, the pitch goes sharp. If I practice vibrato in isolation it doesn't happen, but the intonation tends to rise in a musical context, and I don't know why or how to control it better. What would you do in my situation? How would you practice it? Thanks for your time!
Good to hear from you. The problem you’re talking about is an interesting one. I think you may want to try practicing your vibrato by only going BELOW the pitch. When you practice vibrato, think of the center of the pitch being the highest point and bend the pitch only on the low side. Some people think of vibrato as being both above and below the pitch, but I generally prefer to only adjust the pitch on the low side. Try experimenting with this and see if it helps. If you want to add a visual element, you can experiment with doing slide vibrato this way. Keep the pitch steady with your lips, then gradually add slide vibrato, only moving the slide position lower than the center of the pitch.
A quick Google search reveals that this topic has gotten a fair amount of coverage in different string player forums. You can also take a quick trip to YouTube and watch many of your favorite violinists and cellists play. A lot can be learned from studying the vibrato of string players because, unlike brass players using lip vibrato, the speed and width can be seen. I think you will notice that they mostly vibrate below the pitch as well. I hope this helps. Good luck!