Right now i am listening to 3121, and it occurs to me again how much this album reminds me of his second album 'Prince'.

I mean, 'Prince' was recorded quickly and aimed to be commercially interesting, after Prince went far over his recording budget for 'For You'. He has stated that himselve in interviews.
I dont know if 3121 is recorded quickly, but at least it also sounds as album made for the 'commercial market'.
What both records share also is: they have no kind of real concept that binds the songs together. On both records Prince seems to focus mainly on delivering wellwritten, commercial songs without too much freaky edges or sound experiments, and with quite general lyrics.
On both 'Prince' and '3121' he sounds like he is purposely trying to reach as many listeners as possible, both sound like 'calculated' records, but with enough style and quality to say Prince is 'selling out'.

Those comparisons (at least IMO) made me think about other possible pairings of albums. I came up with these:

Dirty Mind - The Black album
The material on both albums was originally intented for 'private purposes only'. In 1981 his managers convinced him to officially release Dirty Mind (a collection of demos in essence), while The Black Album (mainly recorded in a week long jamsession with his touring band) was, as we all know, first withdrawn from an official release, and later officially released by WB.
Both records can also be compared lyricwise: those are (even) more x-rated and controversial then the lyrics on his other records (1999 excluded maybe). Prince
is sounding like he just wants to sing about one of his favorite objects: Sex, and doesnt tone down lyrically.
Another thing those records share is that on both he is mainly focussing on funk and funk-rock. Alltough you might say the Black album is also influenced a lot by 1999 also.

Lovesexy - The Rainbow Children
While Dirty Mind and The Black Album focus on sex and funk, these two albums lyricwise focus on spirituality and religion. Lovesexy seemed as an attempt to inform and inspire us with the spiritual development seemingly Prince went through in 1987 and 1988. The Rainbow Children is about Prince expressing his new found faith as an Jehovah witness.
Musically both records share the element that Prince doesn't sound too concerned with being commercially attractive and that leads to two musically uncrompomising records.
Both records also share a big jazz influence, with that i dont mean i say they are really 'jazz-records' or even 'fusion records', but on both records he uses different elements that are more common to jazz music then (mainstream) pop music: dissonant horn parts, harmonies in a different key, more unusual chords, songs stretched longer to give room for improvisations and jamming.

For me these are the most obvious 'pairings', but (maybe with a bit more imagination) there are other pairing possible:

Purple Rain - Graffiti Bridge
Both soundtracks to a movie starring The Kid and his competitor Morris, Both mixing music by 'musicians' with electronic sounds, both showing messianic references in the lyrics. To me, Graffiti Bridge always sounds as a (bit flawed) attempt to recapture the elements of Purple Rain.

Around the world in a day - Emancipation
Musically? Not really, or not at all even. But when it comes to the intentions Prince had with both records? Prince became a worldwide star with Purple Rain, Around the world in a day was a purposely left turn, saying to the public 'I am not someone to pin down, this is wat i do'.
When Around the world in a day was a reckoning with stardom, Emancipation was a reckoning with WB, at least on surface. IMO Prince around that time was 'projecting' a lot of inner turmoil at WB. On the outside it seemed like he was fighting WB, who threatened him, in his opinion, as a 'slave', but on the inside Prince seemed busy fighting inner ghosts (judging the Oprah interview, him going 'underground', his sometimes weird behaviour: the whole 'slave' thing, Tora Tora etc.). I mean: sometimes fans accuse Prince of not giving all of himselve in his music and lyrics, but his actions around that time IMO clearly show a troubled soul.

Anyone else here sees those resemblances between those records? And, maybe you have other pairs of albums who you think are 'twins'?

There was just a thread on this, but it basically paired the albums in more obvious ways, based on Prince's evolution--Diamonds & Pearls and Symbol, For You and Prince, Dirty Mind and Controversy, 3121 and Musicology

You're coming from a more thoughtful perspective.

You could find similarities between any of Prince's albums if you look hard enough

'Prince' and 'High'.

Hello,

I can see the similarities more in the production qualites of the albums and
by comparing Prince's albums and his other artists albums.

After Parade the sound quality seems consistent.

For You
Dirty Mind
1999
and ATWIAD seem to have a Demo quality. Maybe Black Album, Chaos and Disorder, and the vault fit here too.

While

Prince
Controversy
Purple Rain
Parade and most of the rest have a more polished sound.

Depends on how much time he had to work on the albums.

RedKite said:

I think to some extent it's where he recorded them, too. For example, I think Controversy was recorded more in a professional studio than Dirty Mind

Riverpoet31 said:

That is misinformation, it's a collection of "single" songs from 1986 & 1987, i.e. from Camille album (Rockhard...), Sheila E. party tape (superfunky..., dead on it), even the most band-sounding 2nigs... is Prince on all instr. with maybe sheila on drums/perc.

Well, I can see your "mating" point of albums, LS/TRC I really soulmates, whereas DM & TBA are rather partners in crime.