README.md

@@ -109,10 +109,18 @@ matcher. The line to watch is:
 unmatched by an artist the library holds: N pairs, M plays
 ```
 
-That is a track that was played, sitting beside a file it should have matched.
-Those are the matcher's real misses, and every one is a candidate for being
-wrongly called cold in stage four. The report lists the worst fifteen by play
-count so they can be eyeballed.
+That is a track that was played by an artist the library holds. It is then
+split again, because owning an artist is a weak proxy for owning a track:
+
+- **the title exists under another artist** — an attribution disagreement, a
+  remixer or a guest billed as the artist. These are the genuine misses, and
+  each is a candidate for being wrongly called cold in stage four. The report
+  names the artist the library files them under.
+- **the title is nowhere in the library** — never bought. No amount of matching
+  conjures a file that does not exist.
+
+Counting both as matcher failures overstates the problem and would over-block
+the cull. The report lists the worst of each by play count.
 
 ## How the ingest works
 

music_curator.py

@@ -1119,12 +1119,55 @@ def coverage_report(store):
         "   AND EXISTS (SELECT 1 FROM lidarr_artist a WHERE a.norm_name = k.norm_artist)"
     ).fetchone()
     logger.info(
-        "unmatched by an artist the library holds: %d pairs, %d plays -- these are the"
-        " matcher's misses, not music you do not own",
+        "unmatched by an artist the library holds: %d pairs, %d plays",
         suspect["pairs"],
         suspect["plays"],
     )
 
+    # Owning an artist is a weak proxy for owning a track, so that figure alone
+    # overstates the matcher's failings. Split it. A title the library holds
+    # under some other artist is an attribution disagreement -- a remixer
+    # credited as the artist, a guest billed as one -- and is a real miss. A
+    # title the library does not hold at all was simply never bought, and no
+    # amount of matching will conjure it.
+    attribution = store.connection.execute(
+        "SELECT COUNT(*) AS pairs, COALESCE(SUM(plays), 0) AS plays FROM scrobble_key k"
+        " WHERE k.track_id IS NULL"
+        "   AND EXISTS (SELECT 1 FROM lidarr_artist a WHERE a.norm_name = k.norm_artist)"
+        "   AND EXISTS (SELECT 1 FROM lidarr_track t WHERE t.norm_title = k.norm_track)"
+    ).fetchone()
+    logger.info(
+        "  of those, the title exists under another artist: %d pairs, %d plays"
+        " -- attribution disagreements, and the genuine misses",
+        attribution["pairs"],
+        attribution["plays"],
+    )
+    logger.info(
+        "  the rest, %d pairs, %d plays: you own the artist but not the track",
+        suspect["pairs"] - attribution["pairs"],
+        suspect["plays"] - attribution["plays"],
+    )
+
+    mismatched = store.connection.execute(
+        "SELECT k.artist, k.track, k.plays,"
+        "       (SELECT a.name FROM lidarr_track t"
+        "          JOIN lidarr_artist a ON a.id = t.artist_id"
+        "         WHERE t.norm_title = k.norm_track LIMIT 1) AS filed_under"
+        "  FROM scrobble_key k"
+        " WHERE k.track_id IS NULL"
+        "   AND EXISTS (SELECT 1 FROM lidarr_artist a WHERE a.norm_name = k.norm_artist)"
+        "   AND EXISTS (SELECT 1 FROM lidarr_track t WHERE t.norm_title = k.norm_track)"
+        " ORDER BY k.plays DESC, k.artist LIMIT 10"
+    ).fetchall()
+    for position, row in enumerate(mismatched, start=1):
+        logger.info(
+            "  attribution %2d: %-45s %4d plays, filed under %s",
+            position,
+            f"{row['artist']} - {row['track']}"[:45],
+            row["plays"],
+            row["filed_under"],
+        )
+
     with_files = store.scalar("SELECT COUNT(*) FROM lidarr_track WHERE has_file = 1")
     played = store.scalar(
         "SELECT COUNT(DISTINCT k.track_id) FROM scrobble_key k"

tests/test_music_curator.py

@@ -732,3 +732,34 @@ def test_a_bracketed_guest_credit_matches_the_bare_tag(tmp_path):
     method, track_id = verdict(store, "Yellowcard", "Here I Am Alive (feat. Someone)")
     assert method == "name"
     assert track_id is not None
+
+
+def test_misses_are_split_by_whether_the_library_holds_the_title(tmp_path):
+    """Owning an artist is a weak proxy for owning a track. Counting both as
+    matcher failures overstates the problem and would over-block the cull."""
+    store = indexed(
+        tmp_path,
+        [
+            # The library holds "Hells Bells", but under AC/DC, not Yellowcard:
+            # an attribution disagreement, and a real miss.
+            scrobble_of("Yellowcard", "Hells Bells"),
+            # Yellowcard is in the library; this track is not, under any artist.
+            scrobble_of("Yellowcard", "A Single She Never Bought"),
+        ],
+    )
+
+    def count(extra):
+        return store.connection.execute(
+            "SELECT COUNT(*) FROM scrobble_key k WHERE k.track_id IS NULL"
+            "   AND EXISTS (SELECT 1 FROM lidarr_artist a WHERE a.norm_name = k.norm_artist)"
+            f"  {extra}"
+        ).fetchone()[0]
+
+    assert count("") == 2
+    assert count("AND EXISTS (SELECT 1 FROM lidarr_track t WHERE t.norm_title = k.norm_track)") == 1
+
+
+def test_the_report_survives_the_attribution_split(tmp_path):
+    store = indexed(tmp_path, [scrobble_of("Yellowcard", "Hells Bells")])
+
+    music_curator.report(store, NOW)