Re: [abcusers] Re: Initial repeats
On Tue 08 Jan 2002 at 09:14AM -0500, Laura Conrad wrote: James == James Allwright [EMAIL PROTECTED] writes: James Someone incorrectly writes: : James is adamant that abc2midi won't play a repeat unless there's : a balanced begin/end. James Damn! Take a day off work and someone decides to put nonsense words James in your mouth! Just for the record, abc2midi does have code in there James to guess the start of repeats when the start of repeat is missing. It was me. If there's code in there, it doesn't work consistently. Attached is a score with four parts, two of which (like most printed music) don't have begin repeats at the beginning of the piece, and the MIDI file which results from running the score through abc2midi. This is not a reasonable test. Why would you be inconsistent in multi-voice music like this ? My recollection is that the guessing is turned off for very complicated cases on the grounds that if the user is capable of using these advanced features, they can get the repeats right and automagic correction is more likely to be a nuisance than a help. If you try a single voice with an end-repeat, you will find that the start-repeat is inserted by abc2midi. James Allwright To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
Re: [abcusers] Re: Initial repeats
Someone incorrectly writes: : James is adamant that abc2midi won't play a repeat unless there's : a balanced begin/end. Damn! Take a day off work and someone decides to put nonsense words in your mouth! Just for the record, abc2midi does have code in there to guess the start of repeats when the start of repeat is missing. My point is that missing out a start repeat is bad notation; an anacrusis at the start of a piece generates ambiguity and I think you will be hard pressed to find a music textbook that legitimizes the process of missing off start repeats. James Allwright To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
Re: [abcusers] Re: Initial repeats
I beg to differ. (Incidentally Scarce Of Tatties is a jig that I rather like - it's in Sue Songer's Portland Collection). Version 1 - stripped to the bone X:1 K:A Mix Aee efg|edB A3:| aea a2e |edB A3:| is incorrect ABC but can be fixed up by guessing (YES, GUESSING!!) where the two repeats are supposed to go. The start of tune one works in this case - but I've seen too many where there are a few lead-in notes at the start of the tune that are not repeated. On these, the guess goes wrong. Some redundancy can be a good thing. Version 2 X:2 K:A Mix Aee efg|edB A3:: aea a2e |edB A3:| is still incorrect, but now there's only one error, i.e. one missing repeat-start. Arguing that O'Neil did it is flawed because as far as I know he never wrote any ABC. Arguing that there is so much ABC out there that does it that it has to be treated as de facto legal, alas, carries the day. This is what it says in the Muse source code: // Algorithm: // Keep count of the number of excess start-repeats. // If we arrive at the end with an excess, close them all // (We could consider doing so as soon as we see a start-repeat // as nested repeats are rare) // We keep track of the last good point to add a repeat and if ever // the count goes negative insert one there. Good points are the beginning // just before the first note or rest and after any repeat-end or double bar, // again just before the first note or rest. Version 3 X:3 K:A Mix |:Aee efg|edB A3:| |:aea a2e |edB A3:| Is correct. It does NOT have an empty bar because :| is not a bar line and nor is |:. The proof of this is that they can occur in the middles of bars. They are something pretty close to double-bars, which can also occur in the middles of bars (I believe the posh word is anacrusis). There seems to be a convention in tadpole land that where a double-bar coincides with a bar line you omit the bar line - that is you draw just two, not three - and I remember wrestling with some interesting ambiguities in the area of bar-length counting and stress-patterns when I wrote that part of Muse. Alas, I cannot now remember what they are. (I think there was (and may still be) a restriction in Barfly that repeats are only allowed at bar boundaries - but I also recall Phil admitting that is a restriction in Barfly caused by a misunderstanding when he wrote it. Laurie - Original Message - From: Jack Campin [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Sunday, December 16, 2001 1:58 AM Subject: Re: [abcusers] Re: Initial repeats A somewhat trickier problem is that there's currently a fair amount of abc tunes that don't even use the initial repeat on second and later sections. Some users seems to think that :| is a fine way to start a repeated section. This is also what many printed sources do, e.g. Kerr's Merry Melodies (as popular as all other Scottish tunebooks put together and then some) and the Northumbrian Pipers' Tunebooks (later numbers of which were typeset with abc2mtex, but I haven't seen those). It eliminates a bit of pointless visual clutter, which is why I use it. Humans and computers are equally able to work out where the repeat starts without an explicit mark. There is a problem with repeats in the middle of tunes that has never been discussed here as far as I can remember, and is mostly ignored by the 1.6 standard as it only discusses the staff notation generated by repeat signs, not their interpretation as music or the semantic constraints on them. Consider this typical piece of coding: X:1 T:Scarce of Tatties M:6/8 L:1/8 K:A Mix Aee efg|edB dBG|Aee efg|edB A3 | aaa gag|fgf eAA|Aee efg|edB A3:| aea a2e |g2f eAA|aea a2e |gaf e3 | eee AAA|d2f fee|Aee efg|edB A3:| Now this: X:2 T:Scarce of Tatties M:6/8 L:1/8 K:A Mix Aee efg|edB dBG|Aee efg|edB A3 | aaa gag|fgf eAA|Aee efg|edB A3:: aea a2e |g2f eAA|aea a2e |gaf e3 | eee AAA|d2f fee|Aee efg|edB A3:| And this: X:3 T:Scarce of Tatties M:6/8 L:1/8 K:A Mix |:Aee efg|edB dBG|Aee efg|edB A3 | aaa gag|fgf eAA|Aee efg|edB A3:| |:aea a2e |g2f eAA|aea a2e |gaf e3 | eee AAA|d2f fee|Aee efg|edB A3:| Version 1 is the Kerr's/NPTB style I use. In BarFly, version 2 produces a butt-ugly two-sided repeat sign at the end of the second line with the dots floating out in space at the margin; the result is that I never use double-sided repeats unless I know for sure that they're going to be displayed in the middle of a staff line. I like the edge of the staff to form an absolutely definite margin with no bits of notation hanging outside it. Version 3 *should* produce an error warning, as there is an empty bar between lines 3 and 4; this is no different from writing the first two lines as Aee efg|edB dBG|Aee efg|edB A3 | |aaa gag|fgf eAA|Aee efg|edB A3:| which BarFly correctly flags as an attempt to write a bar shorter than the time signature says. (In fact BarFly doesn't see the problem in 3, though according to the 1.6 standard
Re: [abcusers] Re: Initial repeats
On Mon, 17 Dec 2001, James Allwright wrote: My point is that missing out a start repeat is bad notation; an anacrusis at the start of a piece generates ambiguity and I think you will be hard pressed to find a music textbook that legitimizes the process of missing off start repeats. From The Norton Manual of Music Notation, First Edition (Heussenstamm, 1987): If a passage is to be repeated from the beginning of a piece, only one repeat sign is needed. John To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
Re: [abcusers] Re: Initial repeats
Ah. I do apologise for maligning your software! L. - Original Message - From: Phil Taylor [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, December 17, 2001 7:27 PM Subject: Re: [abcusers] Re: Initial repeats Laurie Griffiths wrote: (I think there was (and may still be) a restriction in Barfly that repeats are only allowed at bar boundaries - but I also recall Phil admitting that is a restriction in Barfly caused by a misunderstanding when he wrote it. No, repeats can go anywhere, and don't have to coincide with metric bars. The limitation you are probably thinking of is that BarFly won't produce a line break in the music unless there's a bar line (any kind) at the end of the line. Phil Taylor To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
Re: [abcusers] Re: Initial repeats
A somewhat trickier problem is that there's currently a fair amount of abc tunes that don't even use the initial repeat on second and later sections. Some users seems to think that :| is a fine way to start a repeated section. This is also what many printed sources do, e.g. Kerr's Merry Melodies (as popular as all other Scottish tunebooks put together and then some) and the Northumbrian Pipers' Tunebooks (later numbers of which were typeset with abc2mtex, but I haven't seen those). and I could have added that O'Neill's 1001 did the same thing (probably influenced by Kerr, the layout is generally similar). Which implies that pretty much everybody who's seen book versions of the material that forms the bulk of the ABC corpus will be used to repeats written the way I do it. I also checked the oldest piece of music paper I've got, a manuscript from 1816 that contains Scottish music and Mozart piano pieces, and the people who compiled that did it the same way, systematically all through. So Kerr didn't invent this. (To be more precise: the convention is that you use a double-sided or left repeat if it occurs in the middle of a line, but never at either end). I've had a look through my collections and the only ones I can find that ever use a begin-repeat sign at the start of a whole tune are Highland pipe music books. === http://www.purr.demon.co.uk/jack/ === To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
Re: [abcusers] Re: Initial repeats
Jack Campin wrote: Version 3 *should* produce an error warning, as there is an empty bar between lines 3 and 4; this is no different from writing the first two lines as Aee efg|edB dBG|Aee efg|edB A3 | |aaa gag|fgf eAA|Aee efg|edB A3:| which BarFly correctly flags as an attempt to write a bar shorter than the time signature says. (In fact BarFly doesn't see the problem in 3, though according to the 1.6 standard, it should: repeat signs are bars, so the two cases ought to be treated the same way). It used to flag that as an error, but I changed it not to do so, as it occurs in so many tunes. In any case, repeat signs don't always coincide with metrical bars. The commonest case where a repeat sign is not a metrical bar is in a two part tune where the last bar of the first part is shortened to match the anacrusis at the start of the second part. Also, if you want to reorganize the line breaks, you have to edit the adjacent :| and |: signs into a single :: (after all, :||: is illegal). This is a silly timewaster. If you're changing line breaks you shouldn't be forced to change anything *but* line breaks. :||: is not strictly illegal; just a waste of space. The optimal behaviour: write the ABC as in version 2, with a display option in the program to suppress those dangling marginal dots and another option to interpret the :: sign graphically as a closing repeat on one line and an opening repeat on the next. That would decouple the choice of repeat sign from the physical location of its representation in staff notation and allow for all the staff-notation conventions that people have expressed a preference for in this thread. It's on the list of things that BarFly will do when I get around to it:-) (I thought I'd compare my version of that tune with how other people have represented it. But it turned out that all three copies known to the Tune Finder are mine, which I find astonishing considering how familiar it is). : James is adamant that abc2midi won't play a repeat unless there's : a balanced begin/end. I didn't realize this. I haven't used a current version, since I have nothing that will run it, and I soon gave up on the one included with the old abc4mac (0.95?) because it produced too many spurious warnings. Should I put a warning on my site for people not to use abc2midi on anything there? Almost every tune I've transcribed uses the Kerr's/ NPTB convention, and it *must* be easier for a programmer to modify their code to accept them than for me to change all of them. (And no way in hell am I going to change anything until the software I use gives me the option never to see redundant initial repeats in staff notation made from them). I think most people who use abc2midi will be well aware of it. Phil Taylor To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
Re: [abcusers] Re: Initial repeats
John == John Chambers [EMAIL PROTECTED] writes: John My conclusion is that there's no standard for this among printers, at John least in the British Isles and North America. The best advice for John anyone implementing an ABC player would be to expect all of these, John regardless of what any ABC standard might say. But to implement an option that strictly enforces whatever the standard might say. -- Laura (mailto:[EMAIL PROTECTED] , http://www.laymusic.org/ ) (617) 661-8097 fax: (801) 365-6574 233 Broadway, Cambridge, MA 02139 (If I haven't invited you to my party on December 16, I'm sure it's an oversight.) To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
[abcusers] Re: Initial repeats
David Barnert writes: | Laura Conrad wrote: | But it might not be a bad idea for printing programs to provide | an option to not print an initial |:. ... | | This certainly suggests that there is a compelling reason for abc | to require a |: at the beginning of a tune (if the first notes are | to be repeated) even if the printed source omits it. I must admit | I'm at a loss as to what this reason is. Why shouldn't abc assume | that if it can't find a |: before a :| it repeats from the | beginning, as Beethoven's orchestras did? I can't think of a reason either. It's not like there's a serious programming problem finding the start of the tune. In any case, we're dealing with a population of users who can't even be persuaded to include an initial X line in a tune. What makes anyone think we could ever persuade those users to include an initial |: when standard printed music doesn't have it? A somewhat trickier problem is that there's currently a fair amount of abc tunes that don't even use the initial repeat on second and later sections. Some users seems to think that :| is a fine way to start a repeated section. The best approach here might be an education campaign, though I'd have my doubts about its general success. This is probably one of many situations where abc players will always have to deal with malformed abc. The most common cases can probably be dealt with by having players guess that a :| should be considered the start of any subsequent :| if there is no other start-repeat symbol. To subscribe/unsubscribe, point your browser to: http://www.tullochgorm.com/lists.html
