Split an Artist - Title credit stored in TITLE¶

Extract an artist and track title when TITLE contains a predictable credit such as Juniper Vale - Paper Boats. Use Guess Values for the extraction, then trim the two captured fields. This changes metadata; it does not rename the audio file.

Prepare a small practice selection¶

Use copied files with one TITLE value per file and at most one existing ARTIST value. Inspect the existing artist: extraction will replace it when the source matches. The separator in this recipe is one space, a hyphen, and one space: -.

For the expected results below, · marks an ordinary space inside quoted values. It is a display marker, not text to type.

TITLE before	ARTIST before	ARTIST after	TITLE after
`Juniper Vale - Paper Boats`	`Old credit`	`Juniper Vale`	`Paper Boats`
`··AC/DC - North Pier··`	`Old credit`	`AC/DC`	`North Pier`
`Paper Boats`	`Juniper Vale`	`Juniper Vale`	`Paper Boats`
`··Paper Boats··`	`··Juniper Vale··`	`Juniper Vale`	`Paper Boats`
`Kofi - Tide - Quiet Harbour`	`Old credit`	`Kofi`	`Tide - Quiet Harbour`

The final row shows the ambiguity: the parser uses the first delimiter that permits a full match, not knowledge of artist names. If Kofi - Tide is the intended artist, this pattern is wrong for that file. Choose another source, edit that file manually, or use a separately tested pattern for that layout.

Run extraction on one copy¶

Save or discard pending edits and select the first practice file.
Open Actions → Actions (Quick)… and choose Guess Values.
Enter %title% in Source format string.
Enter %artist% - %title% in Guessing pattern.
Choose Apply action and inspect both fields in Extended tags….

The source expression reads the old title before either destination changes. The %artist% and %title% tokens in the guessing pattern name destinations; they do not fetch existing values. The expected first result is ARTIST=Juniper Vale, TITLE=Paper Boats.

This applies immediately. There is no full Guess-Values dry-run preview in this recipe. Test a copied file and compare results before expanding the selection. Use Edit → Undo … for a recorded write when needed.

Add trimming in a reusable group¶

Once the source layout is confirmed, create an Actions… group named Practice split title credit. Add the following rows in Edit actions…:

Step	Action	Field / source	Pattern / format / separator	Replacement / option
1	Guess Values	`%title%`	`%artist% - %title%`	Not used
2	Format Value	`ARTIST`	`$trim(%artist%)`	Not used
3	Format Value	`TITLE`	`$trim(%title%)`	Not used

For row 1, the third column is Source format string and the fourth is Guessing pattern. For the Format Value rows they are Field and Format string. Keep the actions and group, Save groups, then apply only the checked practice group to the intended copies.

Captures preserve their surrounding spaces, so trimming happens after the split. Trimming first would affect only the outside of the combined source; it would not necessarily clean each captured artist/title independently. A source using a different separator, such as Artist – Title with an en dash, does not match this literal hyphen pattern.

The third and fourth example rows are important: Guess Values makes no field changes when the source does not fully match, but the later Format Value rows still run. Thus the complete group can trim fields on a nonmatching file. Restrict the selection to the intended layout if those extra trims are unwanted. A warning from another action also does not stop later actions in the group; inspect every reported file result.

Preview a trim without writing it¶

For a single stored title or artist, Convert → Tag → Tag… can preview $trim(%title%) or $trim(%artist%) with the corresponding destination. Wait for the result, then Cancel if this is only an experiment. This previews the individual expression on the current tags, not the whole ordered group or the tags as they would look after a future Guess Values row.

A bare placeholder reads only the first value. Do not run this group on files with multiple title or artist values when the other values must be preserved, even if the Guess Values row would not match. After extraction, use Tag → Filename as a separate reviewed rename if filenames should also change.

Common mistakes¶

Do not paste a regex such as (.+) - (.+) into Guessing pattern. Guess Values uses named placeholders and literal separators, not capture groups.
Omitting the separator between %artist% and %title% is ambiguous and rejected. The pattern needs text that defines where one capture ends.
The first action overwrites a matching file's artist. Keep a file backup when the previous credit matters; an extra metadata field is not a complete backup of the original file.
Actions write immediately; Save groups only stores the recipe. Check the selected files and undo label rather than pressing Save tags to “apply” the group afterward.