Galdr, from the Old Norse term for ‘incantation’, is the use of song to connect with and utilize the runes. When invoking the power or intention of a rune, it is important to mediate with the runes and grow closer to them, and one way that we do this is through galdr.
To connect with the runes through galdr, focus on the rune in question. Repeat its chant in the lowest tone you can manage, often remaining on a single note; the goal is not to create a pleasant sound, but to vibrate with the same energy as that which is associated with the rune. Through being close with the runes, meditating on them, and performing their galdr, we become more familiar with runic magic and can move on to more active uses of it.
There are many more runic resources here. I will note that it is advised not to perform active runic magic with runes you do not understand and know fully the meaning of; in others words, meditate with and grow close to the runes before employing them in your craft.