The only need imo for 76 keys (or better yet 88) is if you need to regularly play the keyboard as a solo piano in non-arranger mode. I view an arranger keyboard for what it is, an auto-accompaniment style instrument. For this, 61 notes is more than sufficient as allocating 1.5 octaves (C1-F#2) for left hand chords, still leaves 3-1/2 generous octaves, which is only 1/2 octave less than from middle C to the top note on a full 88 note acoustic grand piano. Tyros 4's got conveniently placed transpose buttons directly next the keyboard's lowest key, allowing you to instantly raise/lower the octave so you can play lower bass notes if/when required. Coming from a lifelong acoustic piano background,I feel simply adapting to the octave transpose button method, well worth the gain of the 61 note arranger's much lighter compact portability. For those 'rare' times when a full evening of solo piano repertoire is required, I'll take my lightweight Roland A33 76 note controller, but why have to drag along a larger heavier keyboard otherwise. JMO.