MTV.com writer Kyle Anderson has highlighted the Madonna references featured in the Steven Klein directed video for Lady Gaga's Alejandro:

When the brief preview for Lady Gaga's 'Alejandro' video appeared during the singer's appearance on 'Larry King Live' last week, many people immediately noticed the nod to Madonna's 'Vogue.' It was all there: the sharp black-and-white photography, the muscular dancing, the spartan set, the iconic hairstyle.
But as it turns out, the full version of 'Alejandro' - which premiered Tuesday (June 8) - is a healthy combination of a number of different references, nods and homages to a bevy of Madonna videos. (One MTV News writer says 'Alejandro' is more than just an ode to Madonna - check out his counterpoint in the Newsroom blog.)
The 'Vogue' references are certainly there, as Gaga spends a large chunk of the video in that same spartan set in black-and-white. But the rest of the clip features Gaga in a number of different costumes - including a red nun's habit and some sort of steampunk headgear - in a handful of different scenarios (some of which involve Nazi imagery).
In addition to 'Vogue,' the opening sequence seems to recall Madonna's 'Evita' period (when she made 'Don't Cry for Me Argentina' a hit). Gaga is dressed to mourn whomever is in the casket behind her - perhaps the titular Alejandro? - and it would be easy to assume that she's attending a state funeral, which would mean Gaga flipped the gender roles in the original story of the Peróns (in reality, it was Juan who buried Eva).
Later, Gaga strips to her underwear and dominates a scantily clad dancer tied to a bed. While Madonna is no stranger to the imagery surrounding bondage and submission, that image most faithfully recalls the Material Girl's 'Human Nature,' which saw her dressed in black pleather and dancing seductively with the assistance of ropes and a riding crop.
But the biggest nod to Madonna's past certainly comes with all the religious imagery. Gaga dresses as a nun, swallows rosary beads and stands in front of a row of crosses at various points during the clip, which brings to mind Madonna's classic video for 'Like a Prayer.' In fact, there are even video clips of flames in the background of one of the dance scenes in 'Alejandro,' which could easily have been lifted wholesale from the moment in Madonna's clip when she sings among a field of flaming crosses.
There are a number of other cultural references that slip out of 'Alejandro' (Gaga clearly enjoys the work of film director Fritz Lang), but even the gun-barrel-sporting bra she wears at the end could be mistaken for that conical top Madonna made famous during the Blonde Ambition Tour.
Of course, 'Alejandro' director Steven Klein has worked as a photographer for Madonna over the past few years, so it's quite possible that these are merely the influences he has picked up while working with her. But if Gaga really is making an attempt to define herself as a next-gen Madonna who also pays homage to her elders, then there are worse paths to follow.