Black and White Photography (UK)
Lenswork (USA) No "instruction" but portfolios often feature portraiture - quality of the printed page is superb
Silvershotz (UK/Australia)
Photo Life (Canada) I especially like Richard Martin's columns on composition. Subscription prices are very reasonable.
And while I don't often buy it, I noticed that the May 2007 copy of
Professional Photographer(UK) has a number of articles on music photography (although the magazine focus is on digi photo and very little on film)
Martin