Last week saw the release of 'Valleys Of Neptune', an album which the marketing buzz would have you believe features 'new' Jimi Hendrix material - although if familiar tracks such as opener 'Stone Free' (originally the B-side to 'Hey Joe') are 'new' to you, you might be better off starting with the greatest hits.
In a bid to lend a bit of multimedia zip to what is essentially a collection of anorakish studio offcuts, two videos have been made. The first, for the title track, contains so much in the way of whizzy graphics, it looks less like a loving evocation of 60s psychedelia, more like an MGMT promo. You keep expecting the keyboard intro to 'Kids' to kick in at any moment.
The other, for the track 'Bleeding Heart', is a Julien Temple-directed 'fantasy' in which Hendrix performs at a modern-day Glastonbury, complete with Michael Eavis cameo and Kate Moss watching in the wings (although the verisimilitude stops there - we're not shown, say, a post-show interview with Zane Lowe, or backstage footage of Hendrix in wellies, gingerly navigating the long-drops).
Is this dignified, in any way? Would Hendrix have endorsed this? And, since he's not around to ask, can we watch this stuff with a clear conscience?
Instinctively, the soul shrinks when a musician's image is exploited posthumously - think of those loathsome, mocked-up ad images of Ian Curtis and Sid Vicious wearing Converse trainers that appeared in 2008 (both artists, according to the company's marketing boss, "embodied the values of the brand" - ugh).
But co-opting an artist's likeness is one thing; surely it's even more arrogant to release music in their name? In Hendrix's case, producer Eddie Kramer has made a decent fist of polishing the material, comping vocals, splicing together sections that were in some cases recorded a year apart. It sounds OK. But the awkward fact remains: Hendrix did not authorise these mixes for release.
When an artist's works-in-progress are made public, no-one benefits. I'd argue that Johnny Cash's legacy is not especially enhanced by the emergence last month of 'American VI: Ain't No Grave', a barrel-scraping grab-bag of Sheryl Crow and Kris Kristoffersen covers.
But even when the music is beautiful, the ethics are still dodgy. Shortly before completing 'Grace', Jeff Buckley explicitly stated that he never wanted the opulent-yet-spiteful ballad 'Forget Her' released - but there it is, on all copies of the album released since 2004. Future generations will have no concept of that record without it. Is that right?
Similarly, what is the value - beyond tweaking our morbid curiosity - of an exhaustive archive trawl such as Nirvana's 'With The Lights Out' box-set? I remember, years ago, being swept up in the hype and declaring it a work of "epochal significance" (cringe) in a magazine review - even though, in hindsight, aural doodles like 'Beans' are just the sound of Kurt Cobain dicking about on drugs.
We kid ourselves that those kind of off-guard moments reveal the true musician beneath the studio gloss. In actual fact, they diminish the artist and, in the long run, cumulatively chip away at their dignity.
It is, of course, an understandable impulse to want to hear more from the artists we love. A contrary soul might point out that, if it wasn't for beyond-the-grave releases, we wouldn't have Otis Redding's Sittin' On The Dock Of The Bay, The Dark Knight, or indeed most of Shakespeare's plays.
But let's be brutally honest: posthumous albums invariably suit the commercial interests of the living. They seldom do much for the artistic reputation of the dead.