I came across this in a piece for piano four hands (title and composer are unknown; as pointed out in the comments, it might also be a part of a longer piece). Here's the beginning of the upper part (primo):

Sheet music excerpt, upper part

What does it mean?

  • "♫=♫" - does this indicate straight (as opposed to swing) rhythm?
  • "4T. = 4s." - I don't recognize this at all.
  • "63 𝅗𝅥." - is this equivalent to "𝅗𝅥. = 63", i. e., 63 measures (in 3-4 time) per minute?

More information on the piece:

  • It has 67 measures; measure numbering starts at 1
  • It is printed on two pages per part (upper and lower)
  • No title or composer is given on the first page
  • It appears to be from a book, with the first page of the lower part starting on page number 128
  • It has sections A, B, and C (circled letter, section A starting at measure 9 as shown)
  • It has a coda (starting with a coda sign, 𝄌) that ends with a final bar line (thin and thick vertical line)
  • The last measure before the final bar line is a whole rest in all four hands
  • Curious - by any chance, do you have Piece #40 or #42 in the series? It looks like you have Piece #41.
    – Dekkadeci
    Mar 6, 2022 at 15:10
  • Unfortunately, no. I got this from a friend who is currently trying to find out the origin of the piece, and I will update the question if they find it.
    – Martin
    Mar 6, 2022 at 15:37
  • 4
    The first one could mean "straight", but it might also means something like "L’istesso tempo", so the eigths should have the same tempo as in the previous case. "4 T. = 4 s." might mean something like "4 measures = 4 seconds" (many languages derive their word for "measure" from latin "tactus"), which would coincide with "2. = 63".
    – Lazy
    Mar 6, 2022 at 15:57
  • 1
    Is that a common way of specifying the tempo? I've never encountered it (but I'm not particularly well-versed in musical literature). Also, why would one specify "4 measures = 4 seconds" rather than "1 measure = 1 second"?
    – Martin
    Mar 6, 2022 at 19:11
  • 1
    I added a longer excerpt and some more details. The fact that there is no title on the first page does suggest that this might not be the beginning of the piece; the whole rest at the end might suggest that this isn't the end either. But is it common to start measure numbers at 1 after a rehearsal mark? And would we expect a final barline at the end of the coda in this case?
    – Martin
    Mar 7, 2022 at 16:54

1 Answer 1


Let's talk at least about what we can know. First of all: The standard way of indicating a tempo is in bpm, with an indication of what kind of note value that bpm pulse measures. For instance, ♩ = 120 m.m. (The "m.m." stands, not for "metronome marking," but for "Maelzel's metronome").

There seems to be some ambiguity about the time signature and the pulse. The mention of a dotted half note and 63 seems to mean that you might choose to feel the pulse "in 1," counting only the downbeats (thus, a dotted-half at a time), and that this pulse would be at 63 bpm. This seems reasonable, since a quarter note pulse at that speed is 189, which is not crazy but perhaps a bit hectic to "feel" as the main pulse.

Next: When we see "[note value] [equals sign] [some other note value]", that tends to tell us something about how to handle a transition in tempo or meter. For example:

enter image description here

... This is telling us that the quarter note pulse of the new 3/4 meter continues at the same tempo as the dotted quarter of the 6/8. So the "eighth notes equals eighth notes" in the mystery notation might relate to material that came before. Even if this is the start of a piece (and the measure number on the second system says it is), perhaps it's "piece number 41," and continued attacca from #40.

The music itself shows some metric ambiguity. It settled on 3/4, and the second measure reinforces that with three big quarter notes, but the first measure subverts it with an accent in the middle of the bar. Combined with the possibility of feeling "in 1," it might shift in and out of subdividing as either three groups of two or two groups of three. I have wondered whether the "s" in "4 s." is sextuplet, or whether " 4 t." is some kind of indication of "4-tuplet," but these theories don't add up to something clear. At any rate, the equals sign seems to suggest that "4t. = 4s." is continuing to talk about the relationship of this section to what came before.

  • In my experience it's M.M. ♩ = 120 or ♩ = 120 b.p.m.
    – phoog
    Mar 7, 2022 at 23:36
  • Note that in the original "4T. = 4s." it's a capital T, but a small s.
    – Martin
    Mar 8, 2022 at 16:05
  • 1
    @Martin True, though I've been debating with myself about whether we're looking at something handwritten or typeset, and leaning toward handwritten. The treble clefs appear identical, but that could just be manuscript paper. The time signature characters look different between the two staves; the "f" in "mf" is different than "f"; the "8"s are different. These could all be artifacts of a scanning process, but maybe not. So anyway, it might just be that the "s" is a capital and has been written smaller... Though otoh, the handwriting is meticulously detailed. Mar 8, 2022 at 16:20

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