FyreWulff's Next Gen Guide To Quickly Expanding Your Rock Band Library, 2017 edition
Rock Band Track Packs
Check your favorite retailer, new copies only
Physical disc releases that contained a collection of DLC songs you could play. You need the copy that matches your console family: PS3 for Playstation, Xbox 360 for Xbox. PS2 Track Packs do not come with a code for PS3 (and yes, this has come up). Remember, you need to get a NEW copy, because it's a DLC code on the manual. You don't need the PS3 or 360 to export, just put the code in on the Redeem Code website for the specific platform.
Special note: The AC/DC Track Pack is still the only way to get those songs.
Value: 65 cents per song . Average price of a Track Pack is 13$.
Rock Band: Green Day
While the game's export has officially expired the entire disc setlist is available on the store as regular DLC in album packs and singles. It will cost somewhere slightly north of 65$ to buy it all as DLC if you buy as much of it as album/song packs as possible.
Rock Band Rivals
Originally releasing as just an expansion with the Rivals game mode and Rockumentary, buying Rivals now entitles you to a bunch of free songs. Specifically, 26 of them.
24 of these tracks are automatically added to your game via the latest patch, so updating your game is required to get at them. Four of them require you to download them from the music store for free. Search the store for these tracks after buying Rivals:
"Sweater Weather" - Parks
"To My Romeo" - Spirit Kid
"Black Seas" - Arctic Horror
"(You're) Breakin' Up" - The Black Cheers
Also, you need to own Rivals to play online. So that's a thing.
Value: $1.15 per song . Rock Band Rivals costs 30$ US as of this post. More free songs may be continually added, but are not guaranteed
Free DLC
Two free songs by EVE developers Permaband are available in the store to both base and Rivals expansion owners. Search "Permaband" in the store to get them.
Songs Re-released
This used to be the part of the post where I listed the RB3 version re-releases, but since then Harmonix has started the Rock Band Rewind program, where they re-license songs out of previous game discs and sell them as singles. Simply go into the music store and find the "Rock Band Rewind" category to view all of them. Purchasing Rewinds are the same as if you got the song via the export, so they're compatible with disc exporters online and have all the original features and quirks. A lot of people own these songs, and are generally well known hits, so it's a good idea to pick them up! Please note that even though Rock Band 3's export is currently available, they are also selling some RB3 songs via the Rewind program, so make sure to buy the RB3 export to avoid double-buys if you're interested in that export.
Special note: if you are coming back from RB3, and you bought any (RB3 Version) in that game, the RB3 and RB1/2 versions of songs have now been consolidated. So if your friend only had We Are The Champions as a Lego export, but you bought it as the RB3Version DLC, you can now play it together. The consolidated versions are the RB3 Version's chart.
Rock Band 3 Export
The best value in disc exports in Rock Band in 2017. This 15$ export gets you all 83 songs from Rock Band 3! It's easily the best value for songs by a large margin, and has plenty of chart toppers and indie diamonds, any of these songs sound familiar to you?:
Smoke on the Water - Deep Purple
Free Bird - Lynyrd Skynyrd
Imagine - John Lennon
Bohemian Rhapsody - Queen
Space Oddity (aka Ground Control to Major Tom) - David Bowie
Walk of Life - Dire Straits
Rainbow in the Dark - Dio
Crazy Train - Ozzy Osbourne
Normally if these songs were regular DLC, you be paying 16$ to get them. With the RB3 Export, you can get them for 15$ and 75 other tracks come along for the ride. Whoa.
To get the Rock Band 3 export, you need to have played Rock Band 3 while connected to PSN or Xbox Live with an actual account from an actual PS3 or 360. Used or borrowed copies also work for this.
Note: Imagine has had the Keytar chart moved over to Guitar in RB4, so it supports all 4 instruments.
Note2: It is likely the RB3 export will last for 5 years like previous exports, so it will likely expire around 2020. Don't wait, get it ASAP!
Value: 18 cents per song
DLC with multiple versions - covers
Be careful to make sure to get the originals if you like these songs. Don't ask why Harmonix brought their inhouse covers forward as RB4 DLC. We don't know either.
"Limelight" and "Working Man" by Rush have both HMX covers and originals as DLC. "Tom Sawyer" has the original version as DLC, the cover was only available via the now expired RB1 export.
"Fortunate Son" by CCR has both a HMX cover and the original on the store.
"Sound of Silence" by Simon & Garfunkel also has Disturbed's recent cover on the store.
"Ring of Fire" by Johnny Cash also has Social Distortion's cover on the store.
"Ice Ice Baby" by Vanilla Ice has Queen's cover of this chart hit on the store under the name "Under Pressure".
DLC with multiple version - live/alternates
"Band on the Run" by Paul McCartney has both a Live and the original studio version on the store.
"Poker Face" has both the Lady Gaga original and the Cartman parody from South Park as DLC on the store. The Cartman version was supposed to be expired but is still on the store, so if it works for you, yay!
Special Note to Cross Generation completionists
If you are somewhat interested in going back and playing the old games with DLC you buy today, there is something you need to know. All DLC released after RB4's debut is for Rock Band 4 only.
DLC that released after RB3's debut is RB3 only.
DLC that released before RB3's debut works in both RB1 and RB2, and if it was "family friendly", Lego Rock Band.
If you are on Playstation, you don't need to do anything special. Even if you buy a compatible song via Rock Band 4, you will be given the entitlement to that song for PS3. Buy without worry!
If you are Xbox, you're going to have to do a little more work. The entitlements only go in one direction - from the 360 to the One. So if you're interested in playing legacy DLC in a 360 title, you must buy the song via the 360 Web Store or an Xbox 360 first. Once you do so, the song will immediately be entitled to you on the One via your Ready to Install. If you're not interested in having songs cross-gen, then you don't need to care about this at all.