In this video I show how to use the Superlocrian mode (nothing more than the 7th mode of a minor melodic scale) to improvise over altered chords. On C7 the choice would be C Superlocrian C, Db,Eb,E, F#,G#,Bb (also known as Db melodic minor starting from C). Listen to a few examples of resolution from C7(alt) to F major and to F minor in the second part of the video.
Altered chords are a flavour of dominant chords, where we add certain extensions: #9,b9,#5,b5. In the example on the video I use C7 as basic chord and add the extension D#,Db,G#,Gb also as combinations.