To search for a song in the current playlist, press ⌘-F (command-F mac, or control-F windows). To search for a song in the Library, press ⌘⇧-F. Searching will search every visible column, so to make search go faster, hide the columns you don't care about. You can search for multiple terms, and commas and spaces are ignored. For example [beat, love, me] (don't type the brackets) will find all beatles songs that have the words "love" and "me" (as well as any other song with those three terms).
If you just want to find all songs with a comma in the name somewhere, search for [,], as that is a special case where the comma is NOT ignored.
You can also search for a quoted string if you want to include commas or spaces. For example: [", the"], (with the quotes), will find all the songs that have a comma, then a space, then the word "the". The closing quote is optional if the quoted string is the last one you enter.
To search for a number like "Song ID", just type the number. If you *only* type digits into the search field, it will be interpreted as a number and NOT as a string, and it will search numeric fields only, automatically. eg: typing  will find "Song ID" 52, but will NOT find "The B-52s". To search for NON-numeric numbers, add a space to the end, eg, typing [52 ] (note the space?), this will NOT find "Song ID" 52, but it WILL find "The B-52s". Note the Date column is NOT numeric.
You can search only on a specific column by putting the name of the column first, followed by a colon, followed by your search term.
EG: if you search for "bb", you'll get all the songs that you marked as in the key of B flat, but you'll also get all "Abba" songs right? but if you type [key:bb], then you will ONLY search the "Key" column, and only get results in the key of B flat. Note this does not combine with numeric searching, since it is already rather targeted to search only on numeric fields.
To search for something that actually has a colon in it, just put in two colons in a row.
To search "checkbox" columns (like "No Lyrics", "Purchased" etc), use a "1" to mean "checked" and a "0" to mean "un-checked". eg: to search for all purchased songs, type "purchased:1" in the search box!
eg: [artist:,] will find all songs where the artist name is "last, first" style
eg: [artist:", the] will find all songs where the artist name is "<name of artist>, The"
Note that you must enter the target name in the language in which you're running kJams (ie: match the language you see in the sort column header)
There is also a shortcut you can use to avoid typing all that: Just type "s:" to search the "Song Name" column, or type "a:" to search the "Artist" column. These english roman letter shortcuts work regardless of the language that kJams is running in.
If you wish to find the *exact* string you type, not just part of it, prefix the string with '='. For example:
"=Love", will only find songs where any visible sort column has exactly the word "Love" in it (not case sensitive). It will NOT find "Love is all there is".
You can combine this with Targeted Searches:
"singer:=david", will find ONLY a singer who's name is exactly "david", it will NOT find "Jack Davidson"
Why is it slow?
See Slow Searching.