Consider the following snippet from Where Is My Mind (arranged by Maxence Cyrin). Notice how after the first few bars there's a time signature change. Does the key signature also automatically change here (so that all notes are naturals)?

I'm asking because at the beginning of the piece the time and key signatures are shown together, and when all the notes should be played as natural, only the time signature is shown. Therefore I'm wondering if, when later in the piece when only the time signature is shown, this is still the case.

  • Ok actually i have ascertained that the answer is likely no because of the natural sign drawn in right after the time signature change. Can someone confirm this?
    – Cam
    Commented Apr 28, 2015 at 22:13
  • 6
    You're right, key signatures and time signatures are independent. When one changes, it doesn't affect the other. Commented Apr 28, 2015 at 22:22

5 Answers 5


Right after the time signature change you see a natural sign, which would not be necessary for the assumed implicit key signature reset.

Key signatures are very important and therefore very explicit. For a change of the key signature typically all existing accidentals are first neutralized and then the new ones added.

key SignatureChange

  • Neutralizing the old key signature is one convention. Indeed it is the only possibility if the new key signature is null. But if it isn't, then other conventions are used, e.g. just writing the new key signature.
    – Rosie F
    Commented Oct 15, 2019 at 8:44

Think about this a bit more logically.

At the start of the piece the composer needs to indicate the key and the time signature. That's why they are both together; nothing to do with them being related. So either of them changes as and when the composer requires it, independently.


The only time a key signature changes is when the composer labels it as such. Using the image you provided as an example, the piece would remain in E major, until at some point in the song, the composer states that the piece is to be played in let's say G major.


No. A change of time signature does not cancel the prevailing key signature. Neither does it cancel the clef, the tempo indication, the dynamic or anything else. Yes, all these things will normally be found at the beginning of a score. Because they all need to be set up initially. Thereafter each one becomes completely independent.


They have nothing in common.

Well, that is not enterily true.

If you record it and change the speed on the playback not the input source, then you'd be raising a bit the key collaterally :)

  • 5
    A time signature has nothing to do with tempo.
    – Dom
    Commented Apr 29, 2015 at 0:09
  • tempo can be changed accross time signatures if denominator is not the same, at least in an implict way
    – Whimusical
    Commented Apr 29, 2015 at 13:30
  • 2
    No it doesn't. If the quarter note gets the beat and you're playing at a bpm where quarter notes = 100 then that implies that half notes = 50 and eighth notes = 200. So say you go from 4/4 to 7/8 the tempo is the exact same, but what you are counting is different.
    – Dom
    Commented Apr 29, 2015 at 15:16
  • It depends what you consider the beat, the denominator. If you change from 4/4 to 3/4 in a way that the 3/4 takes same time as the previous 4/4 (african rythm) then either you are changing the beat value (common) or either you consider the 3/4 is not a 3/4 at all even if it sounds like a typical one and you assume for theoretical convenience it will be expressed as a 6/8 where a black is a triplet of /8. Just think that in case time signature change implies change on binary/ternary system, you'll never be able to state what you state about 2/8 being 1/4. 3/8 can also be 1/4, /4 & /8 arbitrary
    – Whimusical
    Commented Apr 29, 2015 at 15:49
  • 2
    Then you're changing the tempo AND the time signature...
    – Dom
    Commented Apr 29, 2015 at 15:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.