Just to be clear: it's not just the New Music query that's slow on startup. Here's My Muisic->Genres->German Baroque->Bach, J S:
Code:
[11-04-17 14:28:35.6570] Logging DB Access    >  0.05000s
[11-04-17 14:28:50.5123] DB Access    0.27662 : SELECT COUNT( * ) FROM albums me:
[11-04-17 14:28:56.6211] DB Access    6.10021 : SELECT COUNT( * ) FROM (SELECT me.id FROM contributors me LEFT JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id LEFT JOIN albums album ON album.id = contributorAlbums.album WHERE ( ( ( album.compilation IS NULL OR album.compilation = ? ) AND contributorAlbums.role IN ( ?, ? ) ) ) GROUP BY me.id) count_subq: '0', '1', '5'
[11-04-17 14:29:31.3924] DB Access    0.17556 : SELECT COUNT( * ) FROM (SELECT me.id FROM tracks me WHERE ( me.audio = ? ) GROUP BY me.id) count_subq: '1'
[11-04-17 14:29:32.1337] DB Access    0.17506 : SELECT COUNT( * ) FROM (SELECT me.id FROM tracks me WHERE ( me.audio = ? ) GROUP BY me.id) count_subq: '1'
[11-04-17 14:29:32.2099] DB Access    0.05405 : SELECT COUNT( * ) FROM (SELECT me.id FROM contributors me LEFT JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id LEFT JOIN albums album ON album.id = contributorAlbums.album WHERE ( ( ( album.compilation IS NULL OR album.compilation = ? ) AND contributorAlbums.role IN ( ?, ? ) ) ) GROUP BY me.id) count_subq: '0', '1', '5'
[11-04-17 14:29:41.1004] DB Access    0.13129 : SELECT COUNT( * ) FROM (SELECT me.id FROM tracks me WHERE ( me.audio = ? ) GROUP BY me.id) count_subq: '1'
[11-04-17 14:29:59.6141] DB Access   15.67782 : SELECT COUNT( * ) FROM (SELECT contributor.id FROM genres me JOIN genre_track genreTracks ON genreTracks.genre = me.id JOIN tracks track ON track.id = genreTracks.track JOIN albums album ON album.id = track.album JOIN contributor_track contributorTracks ON contributorTracks.track = track.id JOIN contributors contributor ON contributor.id = contributorTracks.contributor WHERE ( ( contributorTracks.role IN ( ?, ? ) AND ( ( album.compilation IS NULL OR album.compilation = ? ) AND me.id = ? ) ) ) GROUP BY contributor.id) count_subq: '1', '5', '0', '189'
[11-04-17 14:29:59.8249] DB Access    0.20446 : SELECT SUBSTR(contributor.namesort, 1, 1), COUNT( DISTINCT(contributor.id) ) FROM genres me LEFT JOIN genre_track genreTracks ON genreTracks.genre = me.id JOIN tracks track ON track.id = genreTracks.track JOIN albums album ON album.id = track.album LEFT JOIN contributor_track contributorTracks ON contributorTracks.track = track.id JOIN contributors contributor ON contributor.id = contributorTracks.contributor WHERE ( ( contributorTracks.role IN ( ?, ? ) AND ( ( album.compilation IS NULL OR album.compilation = ? ) AND me.id = ? ) ) ) GROUP BY SUBSTR(contributor.namesort, 1, 1) ORDER BY contributor.namesort COLLATE en_US : '1', '5', '0', '189'
[11-04-17 14:30:01.1113] DB Access    1.28037 : SELECT COUNT( * ) FROM (SELECT me.id FROM albums me LEFT JOIN tracks tracks ON tracks.album = me.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id WHERE ( ( genreTracks.genre = ? AND me.compilation = ? ) ) GROUP BY me.id) count_subq: '189', '1'
[11-04-17 14:30:01.3416] DB Access    0.21421 : SELECT contributor.id, contributor.name, contributor.namesort, contributor.musicmagic_mixable, contributor.namesearch, contributor.musicbrainz_id FROM genres me LEFT JOIN genre_track genreTracks ON genreTracks.genre = me.id JOIN tracks track ON track.id = genreTracks.track JOIN albums album ON album.id = track.album LEFT JOIN contributor_track contributorTracks ON contributorTracks.track = track.id JOIN contributors contributor ON contributor.id = contributorTracks.contributor WHERE ( ( contributorTracks.role IN ( ?, ? ) AND ( ( album.compilation IS NULL OR album.compilation = ? ) AND me.id = ? ) ) ) GROUP BY contributor.id ORDER BY contributor.namesort COLLATE en_US  LIMIT 26: '1', '5', '0', '189'
[11-04-17 14:30:01.4549] DB Access    0.08773 : SELECT COUNT( * ) FROM (SELECT track.id FROM genre_track me JOIN tracks track ON track.id = me.track WHERE ( me.genre = ? ) GROUP BY track.id) count_subq: '189'
[11-04-17 14:30:03.0110] DB Access    1.55243 : SELECT COUNT( * ) FROM (SELECT album.id FROM genre_track me JOIN tracks track ON track.id = me.track JOIN albums album ON album.id = track.album WHERE ( me.genre = ? ) GROUP BY album.id) count_subq: '189'
[11-04-17 14:30:03.1865] DB Access    0.16818 : SELECT COUNT( * ) FROM (SELECT contributor.id FROM genres me JOIN genre_track genreTracks ON genreTracks.genre = me.id JOIN tracks track ON track.id = genreTracks.track JOIN albums album ON album.id = track.album JOIN contributor_track contributorTracks ON contributorTracks.track = track.id JOIN contributors contributor ON contributor.id = contributorTracks.contributor WHERE ( ( contributorTracks.role IN ( ?, ? ) AND ( ( album.compilation IS NULL OR album.compilation = ? ) AND me.id = ? ) ) ) GROUP BY contributor.id) count_subq: '1', '5', '0', '189'
[11-04-17 14:30:06.7356] DB Access    0.08731 : SELECT COUNT( * ) FROM (SELECT album.id FROM contributors me JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id JOIN albums album ON album.id = contributorAlbums.album LEFT JOIN tracks tracks ON tracks.album = album.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id WHERE ( ( genreTracks.genre = ? AND ( contributorAlbums.role IN ( ?, ?, ? ) AND me.id = ? ) ) ) GROUP BY album.id) count_subq: '189', '1', '5', '6', '9186'
[11-04-17 14:30:06.8623] DB Access    0.12169 : SELECT SUBSTR(album.titlesort, 1, 1), COUNT( DISTINCT(album.id) ) FROM contributors me LEFT JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id JOIN albums album ON album.id = contributorAlbums.album LEFT JOIN tracks tracks ON tracks.album = album.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id WHERE ( ( genreTracks.genre = ? AND ( contributorAlbums.role IN ( ?, ?, ? ) AND me.id = ? ) ) ) GROUP BY SUBSTR(album.titlesort, 1, 1) ORDER BY 0 || album.titlesort COLLATE en_US : '189', '1', '5', '6', '9186'
[11-04-17 14:30:07.0107] DB Access    0.14177 : SELECT album.id, album.titlesort, album.contributor, album.compilation, album.year, album.artwork, album.disc, album.discc, album.musicmagic_mixable, album.titlesearch, album.replay_gain, album.replay_peak, album.musicbrainz_id, album.title FROM contributors me LEFT JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id JOIN albums album ON album.id = contributorAlbums.album LEFT JOIN tracks tracks ON tracks.album = album.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id WHERE ( ( genreTracks.genre = ? AND ( contributorAlbums.role IN ( ?, ?, ? ) AND me.id = ? ) ) ) GROUP BY album.id ORDER BY 0 || album.titlesort COLLATE en_US  LIMIT 159: '189', '1', '5', '6', '9186'
[11-04-17 14:30:08.2146] DB Access    0.08340 : SELECT COUNT( * ) FROM (SELECT tracks.id FROM contributors me JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id JOIN albums album ON album.id = contributorAlbums.album JOIN tracks tracks ON tracks.album = album.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id WHERE ( ( genreTracks.genre = ? AND ( contributorAlbums.role IN ( ?, ?, ? ) AND me.id = ? ) ) ) GROUP BY tracks.id) count_subq: '189', '1', '5', '6', '9186'
[11-04-17 14:30:08.2845] DB Access    0.06469 : SELECT COUNT( * ) FROM (SELECT album.id FROM contributors me JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id JOIN albums album ON album.id = contributorAlbums.album LEFT JOIN tracks tracks ON tracks.album = album.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id WHERE ( ( genreTracks.genre = ? AND ( contributorAlbums.role IN ( ?, ?, ? ) AND me.id = ? ) ) ) GROUP BY album.id) count_subq: '189', '1', '5', '6', '9186'
[11-04-17 14:30:08.3477] DB Access    0.05833 : SELECT COUNT( * ) FROM (SELECT contributor.id FROM contributors me JOIN contributor_album contributorAlbums ON contributorAlbums.contributor = me.id JOIN albums album ON album.id = contributorAlbums.album LEFT JOIN tracks tracks ON tracks.album = album.id LEFT JOIN genre_track genreTracks ON genreTracks.track = tracks.id JOIN contributors contributor ON contributor.id = album.contributor WHERE ( ( genreTracks.genre = ? AND ( contributorAlbums.role IN ( ?, ?, ? ) AND me.id = ? ) ) ) GROUP BY contributor.id) count_subq: '189', '1', '5', '6', '9186'
A 15 second delay just to fetch the artist list within a genre seems like a annoyance...even if it's just for the 1st query of the day.

One odd thing: Having started SBS from the command line as in the previous post, if I then exit SBS via a ctrl-c and then restart SBS, the initial query lag isn't nearly as pronounced. So it seems like there must be some OS involvement in this problem. With a cold OS start (or reboot), this problem seems to be exacerbated.