As you may have read, last week the bridge on my violin snapped in a concert (well actually a man snapped the bridge on my violin but let's not go there!). I've temporarily put a spare bridge on until i can get to my luthier but it's doing some weird things and i don't know what's normal and what's not now!

Other than making annoying noises on the G and E string and stuff that i know isn't normal, i've noticed last night... when i play a D on the G string, the D string vibrates too (loudly). The same if i play an A on the G string - the A string vibrates and sounds loudly, even though i'm not touching the A string! I'm not sure if it's always happened and i've never noticed, or if it's not supposed to happen?

I'm gonna look real silly if that's supposed to happen...!

If the D you are fingering is exactly in tune with the open D then it should set it vibrating. (IMHO )

aaah phew! thanks

i can't believe i've never noticed before!

A bridge needs to be propertly fitted to a violin and needs to be in the right place. A bridge from another violin will not fit properly. You need to go to a luthier and have them fit a bridge. Don't worry, they will not think you are silly for asking them to do that.

I know that, i've already emailed my luthier I was just wondering about the string thing, as i've never heard it so loudly before. Just wondering if it was normal or not so i know what to tell my luthier

I've barely started playing the violin, but have noticed the open strings vibrating and took it to mean that the note was completely in tune with the string.

It's called resonance! Any stretched string has a fundamental frequency which will sound if you pluck/bow it. If that exact frequency is being played close by, resonance occurs and the string will sound without being plucked. That's just physics, and occurs in all stringed instruments.

I don't know why you've been less aware of it before - maybe your intonation is improving? It could be that for some reason the new bridge grips the string differently and allows it to resonate more easily. Or perhaps because you know the bridge isn't the "right" one you're particularly sensitive to how your violin is sounding.

Well i noticed since i started playing the Czardas - you know the first two notes of it, the A up to the next octave A on the G string, i noticed that the note was ringing really nicely so looked at the strings and noticed Other than that i really don't know how i managed to miss that. I've never seen or heard it before.
Though i am really blonde (despite having black hair) and tend to miss really obvious things...

I think it's a mixture of those, and because my violin has had a 'blip' (it really did go BANG when the bridge snapped o_O i know bridges going do make a bang... but i mean... bang :|) so i'm still really worried that there'd something else wrong with it as a result of the bang that i have yet to notice...