If you try to burn more than 70 min onto ANY CD-R, you may find you have problems playing them on normal CD players. This is because we are exceeding the original CD specification, and systems are not obliged to support this.
Compressing the audio is not an option, because normal CD players cannot uncompress. You can certainly remove silence, or chop bits out if you want, but other than that, if you want more music on one disk, you have two options: use MP3/OGG Vorbis encoding and a CD player that can read such disks, or use DVD media and a player that can read DVD audio disks.