Not every song needs something in the "Source" field. The source is only for songs that are "from" something, such as a video game theme song, or something from the soundtrack of an anime. Regular rock and pop songs can just leave the source field blank.
Under "Tags" is where you can put the album title if you choose, along with specific subgenre information.
Here is the FAQ entry for specific details:
Under "Tags" is where you can put the album title if you choose, along with specific subgenre information.
Here is the FAQ entry for specific details:
You should enter this information before you create a second difficulty, to ensure that the text will be consistent across all of the maps in the set.
Artist: The band, singer, or group that performed or created the song. osu! will pull the artist from the mp3 file, but please double check it to make sure it is spelled and punctuated correctly. Anime/Game titles or companies do not belong here. You can usually find the composer for anime and game songs on Wikipedia. Foreign names should be presented in the same name order as used on Wikipedia (generally, Given Name followed by Family Name, the western order, for consistency).
Title: The name of the song. Again, it will be pulled automatically from the mp3 file, but double check for spelling or capitalization errors, especially if you got the mp3 online.
Beatmap Creator: That's you. osu! should handle this automatically, so you shouldn't edit this. If you are including a guest difficulty made by someone else, their name belongs in the Difficulty field below, not here.
Difficulty: While the other fields should be identical between all maps in a set, the Difficulty field is filled differently for each map, to indicate which ones are harder than others. You can select one of the default names, or create your own name. While it's good to be creative, try to make it very clear which one is harder than others -- Ambiguous difficulty names can annoy players. This would also be the field where you indicate a guest mapper, if this is their difficulty (e.g. "Larto's Hard"
Source: This field should generally only be included for Anime or Video Game songs, and occasionally for Novelty (Movies, TV, or Internet) songs. If the song is from an anime or video game, or is most famous for its use as a TV or movie theme, the title of that source goes here. Rock and Pop songs should generally leave the field blank: This is not to be used for things like album titles, and video games like Rock Band or Guitar Hero, which use already-popular songs, should not be named here.
Tags: This is a good place to put sub-genre information, for specific genres not represented on the Beatmap Listing (such as Punk or Metal). If the map is associated with a rhythm game like Rock Band or Guitar Hero, that game can be named here. If the song is from a game or anime, the company that created it can be named here. If your map has "collab" elements mapped by other mappers, their names can go here. Tags are separated by spaces.
Again, to avoid issues, please make sure that everything (aside from Difficulty name) is filled out identically for each difficulty.