Installing xposed framework, and nottach xposed tweaks (you can search for them), will give you a volume button to change tracks options, among other things, and only requires a rooted phone. Very simple to do, you basically just install 2 apks.
Samsung Galaxy S4 i9500 running wanamlite V3.4 Android 4.3 with Adam kernel
Google Nexus7 16GB running JB 4.3 ParanoidAndroid
Samsung Galaxy Note 2 N7100 running rooted stock Touchwiz
Samsung Galaxy S2X T989D on Wind Mobile running CM10-nightlies
Wind Mobile Optimus G2x running Genesis - Stable Build1 - CM9/AOKP Hybrid
T-Mobile HTC HD2 running NexusHD2-ICS-4.0.3-CM9 V2.3 HWA
Need Dropbox? (+500MB)