Ain't nobody got time for me to blather on about all 40 songs (myself included!), so here's some notable mentions...
Welcome to the Black Parade (by Alex Lahey): This song is single-handedly the reason that I purchased this album, and it delivers in spades. It takes a highly captivating song, strips away all the over-produced Hollywood nonsense, and trades the cartoon caricatures for a great sense of authenticity. Brilliant.
I Touch Myself (by Lime Cordiale): A quirky interpretation that trades nicely on the original's catchiness.
Say So (by Polish Club): I'm not familiar with the original, but this version has a nicely syncapated 6/8 groove.
Knowing Me Knowing You (by Angie McMahon): Nicely understated version of the ABBA classic.
Heart-shaped Box (by Hermitude): The sparse yet toe-tapping groove works a treat and makes me enjoy this more than Nirvana's original.
Dance Monkey (by Milky Chance): A quirky and captivating re-interpretation of the original... or maybe I'm just a sucker for anything with an accented offbeat...
Mr Brightside (by Hauskey): I really enjoy The Killer's original version (plus the added irony that it was written by the drummer who left the band afterwards), but this laid-back version feels flat and lacks the orchestration that makes the original sparkle.
Bags (by Dominic Fike): Another one I'm completely unfamiliar with, but the indie-rock groove kicks things off nicely. It goes off into the weeds each time after the chorus, but thankfully this doesn't last too long.
Love is in the Air (by Stella Donnelly): Initially I thought it wasn't a patch on the magnificent energy of the original, but slowly the beautiful vocals are working their way into my affections.
Get Free (by Northlane): Sadly, this adds very little compared to the original.
Don't Start Now (by Azure Ryder): Despite the lack of any particularly memorable moments, this is beautifully crafted pop perfection.
Righteous (by Stand Atlantic): This is probably my favourite r&b song (which is quite a short list) before cranking it up into a rock power-ballad.
California (by Japanese Wallpaper): Wonderful feelgood vibes, like cruising down the PCH on a perfect sunny day. Same goes for Mr Bluesky (by Alex the Astronaut).
When the War is Over (by Jarryd James): Too energetic for its sorrowful lyrics IMHO.
Unwritten (by Maddy Jane): I've forgotten the original, but judged in isolation this song perfectly blends emotion with pop catchiness.
Parlez Vous Francais (by Mickey Kojak): White Stripes (The Hardest Button To Button) meets Basement Jaxx. Brilliant.
Blackfella/Whitefella (by Bad Dreems): Generic styling ala Midnight Oil, but one can't complain when it works this well.
Don't Look Back in Anger (by Yours Truly): Re-interpreting an all-time favourite song of mine is always fraught with danger, but I also dig this more eclectic version. The pre-chorus's chord progression and chorus's lyrics are highlights, as per the original.
Forever Young (Tones and I): The whispy, directionless original holds no appeal to me whatsoever, but this cover has enough craziness make it an interesting experience.
Favourite songs
Welcome to the Black Parade, Knowing Me Knowing You, Heart-shaped Box, Dance Monkey, Bags, Love is in the Air, Blinding Lights, Lady Marmalade, Soaked, Don't Start Now, Righteous, California, No Diggity, Mr Bluesky, 1901, Unwritten, Parlez Vous Francais, Blackfella/Whitefella, Don't Look Back in Anger, Forever Young
Final thoughts
Before doing this post, I was slightly dreading having to pick through all 40 songs. But the list of Favourite Songs shows that there's plenty of wheat amongst the chaff here.