I heard a romanian gipsy fiddler playing dizzyingly rapid tremolo.
How can I achieve that?
Tremolo should be a reflex, not a active fast up/down bow. Almost like a vibrato reflex but with the bow. I don't mean bow vibrato, that is another technique/discussion, just mean tremolo should be unconscious, not forced.
Sometimes tremolo can be very tiring if the right technique is not there. In classical musical typically Bruckner & Schumann write a lot of tremolo for the strings causing pain if not played properly.
The way I suggest to train this is rehearsing "legato", slowly, until it gets natural. Legato exercises are one of the best way to get the fingers in the right hand relaxed so they work as dampers of the arm movement. A bit like a basket ball, if you play it against the floor your arm, hand and fingers will trow the ball but they get back up before you actually think of getting them back to the position. When you play down-stroke legato the fingers follow "after" the bow in a natural, unplanned, unconscious way. Mastering this slow will make your tremolo relaxed, without inner energies that might be a contrary force inside the movement and causing tiredness.
About playing it "gipsy fast" its a result of exercise and relaxation. Like playing fast drills, or the Irish typical bow triplet, it will come naturally the more you play. In the end it gets to a vibration of the hands/fingers, minimized to create a shaking or the bow direction.
I'm not a violinist, but the practice is the same as on guitar.
Start with the fundamentals Find a good few videos on proper bow technique, and tremolo technique. Watch them, then at a very slow speed execute them, and when I say slow I mean uncomfortably slow.
Start Slow So slow that you can focus entirely on geting an even sound, and playing in time(say crotchets at 50-60bpm). This allows you to get control of everything that you just can't think about at rapid speeds.
Speed up gradually My standard practice is to increase by 8bpm once you're comfortable playing at the speed you're on. once you get to double the original speed(around 120 is my line), half the tempo and the note value.
once you've done that continue the process as before. the Idea is that you will get to the point at each tempo of saying "this is too slow, I can play this at 8 more easily" and then when you do speed up you will already be 90% ready for each new tempo. you just need to iron out the little faults ;)
have a target Goal setting is helpful for all practice, including here. Define what dizzyingly fast is from a tempo standpoint, then make that your long term goal. Each time you paractice then set what tempo and note value your current goal for this session and that'll give you an end point that you can practically use today.
Stop if your arm gets tired When your hand gets tired, move on to something else. you've done more than enough if your muscles are getting weak and you don't want to damage your arm! in guitar and piano you should be relaxed especially during technically demanding pieces, and I believe that it's the same for violin. any tension from playing faster than you're ready for can kill your technique, and your playing arm!!!
I asked a violinist friend on Twitter and she said
And I also found a wikihow.
Also, check out I find myself making the same mistake when practising - despite focussing on that part- how to remedy? ,it is along a similar vein to this question.
Hope that helps!