Looking for a tune
To find a tune you can either identify its category (see Tunes) or search for it.
By tune category
When you click on a tune category, you will see a list of incipits, the first few measures of each part (typically there are two parts, but not always).
By search
You can search for words which have special characters (non-English) either directly or as though the accent marks were removed. For example, you can search for “Rättvik” by entering “Rättvik” or “Rattvik”. Except for file names the proper spelling is always used, but almost everywhere the unaccented “spelling” is also available for searching.
Each tune is numbered with a 4-digit arbitrary identifier, starting at 1001. If you know a tune’s number, putting it in the search box is the easiest way to find it.
Keep in mind that there are tunes whose titles include 4-digit numbers. For example, there are two tunes whose names are “1814”. The tune whose tune number is 1814 is a different tune altogether.
Annotations
All tunes have a formally typeset score in the form of a PDF file. Use Adobe Reader to view and print the contents.
Depending on my current (2015) updating activity, the link to a PDF file will be either a text “PDF” or an icon 
.
ABC
At this time (2015) I am in the process of generating ABC notation versions for all tunes. This will take a while… This process also produces new and cleaner incipit images, and is a pre-requisite for converting all incipits pages into mobile-friendly versions, like the Engelska example.
Meanwhile the versions of the old ABC tunes that exist on FolkWiki (see below) are somewhat stale and in need of replacement — I am working with FolkWiki to finalize the best way of adding BlueRose ABC tunes to their site. In the meantime, I have retained the FolkWiki links for those tunes that have them, but I have removed the ABC files themselves and will be replacing them with new examples.
Accented characters appear in ABC files, but when you use your browser to display a linked ABC file you may be dismayed to find that your browser does not properly render the accented characters. This is an old limitation of several browsers that is still present. It you download the linked file instead, you will get the proper accented characters.
ABC files can be opened by any text editor. There are also many free ABC tools available — the one I use is EasyABC.
FolkWiki
Tunes may have a link to FolkWiki, a Scandinavian folk music archive containing ABC versions and additional information. Tunes in common on BlueRose and FolkWiki are cross-referenced (in many cases).
The link to a FolkWiki page is followed by the tune number on FolkWiki.
Recordings
Tunes that originate from workshops may also have a link to an MP3 file of the tune that can be opened or downloaded. Sometimes there is a slow version as well. These recordings are reproduced with the permission of the instructor(s) and are restricted to non-commercial use.
Depending on my current (2015) updating activity, the link to an MP3 file will be either a text “MP3” or an icon 
. The performer(s) names follow the link.
NHP
Most of these tunes are playable on nyckelharpa, and a few are best played on that instrument. Tunes which are particularly comfortable for the nyckelharpa are often notated with NHP, but this is only a sampling of good tunes for ‘harpa. A search on “NHP” will turn up an impromptu but incomplete list.
Transcriptions
Folk music
This is not classical music. See here for a discussion of folk music basics.
Reliability
Transcriptions of tunes come from many hands, including mine, and may contain errors. Sometimes the tune’s name or context is not known to the transcriber. Individual performers play the same tune differently (often in the same performance), the tune itself exists in variants, and ornamentation is individualistic, difficult to notate, and hard to read. It is best to think of these tune transcriptions as skeletons of the melody with much of the performance practice omitted — there is no substitute for listening to actual performances. See this excellent article by Matt Fichtenbaum on the limits of musical transcriptions.
Scandinavian tune names exist in multiple dialects with alternate spellings, personal names and nicknames are creatively rendered, and non-native speakers no doubt miss a few things with regard to spelling and punctuation. If you spot likely errors, please let me know.
Special tunings
Most of these tunes are notated with fiddlers in mind. Scordatura tunes (non-standard GDAE tuning for the violin) are generally notated as fingered not as sounded, unless otherwise mentioned. If you are not a fiddler, this may settle some confusion for you in the notation of such tunes — you can recognize them by the 4-note chord that precedes the first barline (which dictates the tuning of the 4 strings). See Special tunings for more information.
Maps
Look for the maps link (upper right corner) on incipits pages for tune categories that are associated with a particular region. There are many regional styles, and knowing where a regional tune comes from will help you distinguish it from other styles.